diff --git a/docs/CNAME b/docs/CNAME
deleted file mode 100644
index 3d0ec4d52..000000000
--- a/docs/CNAME
+++ /dev/null
@@ -1 +0,0 @@
-funkin.me
\ No newline at end of file
diff --git a/docs/Funkin' Debug Hotkeys.md b/docs/Funkin' Debug Hotkeys.md
new file mode 100644
index 000000000..c560c5422
--- /dev/null
+++ b/docs/Funkin' Debug Hotkeys.md	
@@ -0,0 +1,31 @@
+# Funkin' Debug Hotkeys
+
+`F4` (EVERYWHERE) - Leave Current State and move to Main Menu
+`F5` (EVERYWHERE) - Hot Reload Data Files
+
+`Y` (Title Screen) - WOAH
+
+`~` (Main Menu) - Access Debug Menu
+
+`U` (Play) - Open Stage Editor State
+`H` (Play) - Show/Hide HUD
+`1` (Play) - End Song
+`2` (Play) - Add 10% Health
+`3` (Play) - Subtract 5% Health
+`7` (Play) - (NOT WORKING) Open Chart Editor
+`8` (Play) - Open Animation Editor
+`9` (Play) - (Easter Egg) Classic Health Icon
+`PGUP`/`Fn+Up` (Play) - Skip Forward In Time
+`PGDN`/`Fn+Down` (Play) - 🦃 That's right, we're going to go BACK IN TIME
+
+`F` (Freeplay Menu) - Move to Favorites
+`P` (Freeplay Menu) - Switch to Pico (probably doesn't work)
+`T` (Freeplay Menu) - Start typing in search bar
+`Q` (Freeplay Menu) - Back one letter
+`E` (Freeplay Menu) - Forward one letter
+
+`Arrows` (Stage Editor) - Move Prop
+`Ctrl-Z` (Stage Editor) - Undo
+`Y` (Stage Editor) - Leave Stage Editor
+
+`H` (Pause Menu) - Hide the Pause Menu UI (good for screenshots!)
diff --git a/docs/img/skin-funkin-cardbordtoast.jpg b/docs/img/skin-funkin-cardbordtoast.jpg
deleted file mode 100644
index dd0e96e60..000000000
Binary files a/docs/img/skin-funkin-cardbordtoast.jpg and /dev/null differ
diff --git a/docs/index.html b/docs/index.html
deleted file mode 100644
index 11137c674..000000000
--- a/docs/index.html
+++ /dev/null
@@ -1,60 +0,0 @@
-<!DOCTYPE html>
-
-<html lang="en">
-
-<!-- 
-	@brandybuizel
-	@ninja_muffin2.4
--->
-
-<!--Let's get meta bois-->
-<head>
-	<meta charset="utf-8">
-	<title>Friday Night Funkin'</title>
-	<meta name="description" content="A dope ass rhythm game">
-	<meta name="viewport" content="width=device-width, initial-scale=1.0">
-	<link href="styles.css" rel="stylesheet" type="text/css">
-	<!-- <link href="website/mm.ico" rel="icon" type="image/x-icon"> -->
-	<link rel="shortcut icon" type="image/png" href="../art/icon.png" />
-</head>
-
-<body>
-	<!--Header-->
-	<header>
-	</header>
-
-	
-	<marquee width="1920" scrollamount="2" scrolldelay="10" truespeed="truespeed">Friday Night Funkin</marquee>
-	<!--Hot tortilla wrap-->
-	<div id="wrapper">
-		<h1>Friday Night Funkin' - Rhythm game extraordinaire</h1>
-		
-
-		<div id="coolervidwrapper">
-			<div class='videoWrapper'>
-				<iframe width="560" height="349" src="https://www.youtube.com/embed/HMNKUo3CCpU" frameborder="0"
-				allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
-				allowfullscreen></iframe>
-			</div>
-		</div>
-		
-		
-		<div class="coolBox hovertext" id="twitter">
-			<p class="description">Friday Night Funkin' is a dope ass rhythm game.</p>
-			<p class='description'>It is made by <a href="https://twitter.com/ninja_muffin99">ninjamuffin99 (programmer)</a>, <a
-				href="https://twitter.com/PhantomArcade3K">PhantomArcade (animator)</a>, <a
-				href="https://twitter.com/evilsk8r">evilsk8r (artist)</a>,
-			and <a href="https://twitter.com/kawaisprite">Kawaisprite (musician)</a> originally for Ludum Dare 47.</p>
-		</div>
-
-		<div class="linktext hovertext" id="ng">
-			<a href="https://www.newgrounds.com/portal/view/770371">Play demo on Newgrounds</a>
-		</div>
-
-		<div class='linktext hovertext' id="itch">
-			<a href="https://ninja-muffin24.itch.io/funkin">Support the game on Itch.io</a>
-		</div>
-		
-	</div>
-</body>
-</html>
\ No newline at end of file
diff --git a/docs/readme.md b/docs/readme.md
deleted file mode 100644
index aba261b5f..000000000
--- a/docs/readme.md
+++ /dev/null
@@ -1,7 +0,0 @@
-this is for funkin website stuff
-if you're compiling game, you can ignore this folder completely!
-
-if not, dawg check out [funkin.me](https://funkin.me)
-
-note that i probably won't accept any major pull requests for this
-cuz I wanna make the website as a nice lil project to teach myself HTML and CSS and all that!!
diff --git a/docs/styles.css b/docs/styles.css
deleted file mode 100644
index 5ee1062fb..000000000
--- a/docs/styles.css
+++ /dev/null
@@ -1,97 +0,0 @@
-.coolBox {
-    background: #1a1a1aCC;
-    margin: 40px 4vw;
-    padding: 25px;
-    font-size: 120%;
-    border-radius: 10px;
-}
-
-#wrapper
-{
-    padding: 20px;
-    margin: auto;
-}
-
-marquee {
-    margin: auto;
-    text-align: center;
-    display: inline-block;
-}
-
-h1 {
-    text-align: center;
-}
-
-body {
-    background-image: url('img/skin-funkin-cardbordtoast.jpg');
-    background-repeat: no-repeat;
-    background-attachment: fixed;
-    background-size: cover;
-    color:white;
-    background-color: #000;
-    font-family: Arial, Helvetica, sans-serif;
-    
-}
-
-a { color:inherit;
-  text-decoration: none;}
-
-
-.hovertext a{
-    color:white;
-    text-shadow: 0px 0px #00000077;
-    transition: color 1s, text-shadow 1s;
-}
-
-.hovertext a:hover
-{
-    text-shadow: 2px 2px #00000077;
-    color: #ffb50e;
-}
-
-.linktext {
-    text-align: center;
-    display:block;
-    font-size: 130%;
-    padding-bottom: 10px;
-}
-
-.linktext a {
-    font-weight: bold;  
-}
-
-.linktext a:hover {
-  border-radius: 5px;
-}
-
-#itch a:hover
-{
-    color: #fa5c5c;
-}
-#twitter a:hover
-{
-    color: #00acee;
-}
-
-
-#coolervidwrapper {
-    padding-left: min(12em, 75%);
-    padding-right: min(12em, 75%);
-    min-width: 30%;
-}
-
-.videoWrapper {
-  position: relative;
-  padding-bottom: 56.25%; /* 16:9 */
-  height: 0;
-
-  max-block-size: 1400px;
-}
-.videoWrapper iframe {
-  position: absolute;
-  top: 0;
-  left: 0;
-  width: 100%;
-  height: 100%;
-
-}
diff --git a/hmm.json b/hmm.json
index 52d5ffad8..150a4f242 100644
--- a/hmm.json
+++ b/hmm.json
@@ -24,7 +24,7 @@
     {
       "name": "flixel-ui",
       "type": "haxelib",
-      "version": "2.4.0"
+      "version": "2.5.0"
     },
     {
       "name": "flxanimate",
@@ -38,6 +38,11 @@
       "type": "haxelib",
       "version": "3.5.0"
     },
+    {
+      "name": "hamcrest",
+      "type": "haxelib",
+      "version": "3.0.0"
+    },
     {
       "name": "haxeui-core",
       "type": "git",
@@ -92,12 +97,33 @@
       "url": "https://github.com/EliteMasterEric/lime"
     },
     {
-      "name": "mockatoo",
+      "name": "mconsole",
       "type": "git",
       "dir": null,
       "ref": "master",
+      "url": "https://github.com/massive-oss/mconsole"
+    },
+    {
+      "name": "mcover",
+      "type": "git",
+      "dir": "src",
+      "ref": "master",
+      "url": "https://github.com/massive-oss/mcover"
+    },
+    {
+      "name": "mockatoo",
+      "type": "git",
+      "dir": "src",
+      "ref": "master",
       "url": "https://github.com/EliteMasterEric/mockatoo"
     },
+    {
+      "name": "munit",
+      "type": "git",
+      "dir": "src",
+      "ref": "master",
+      "url": "https://github.com/EliteMasterEric/MassiveUnit"
+    },
     {
       "name": "openfl",
       "type": "git",
@@ -121,6 +147,13 @@
       "name": "tink_json",
       "type": "haxelib",
       "version": "0.11.0"
+    },
+    {
+      "name": "hmm",
+      "type": "git",
+      "dir": null,
+      "ref": "d514d7786cabf18b90e60fcee38399fd44c2ddfb",
+      "url": "https://github.com/andywhite37/hmm"
     }
   ]
 }
diff --git a/source/funkin/Conductor.hx b/source/funkin/Conductor.hx
index 3c6470373..9bd668b69 100644
--- a/source/funkin/Conductor.hx
+++ b/source/funkin/Conductor.hx
@@ -180,9 +180,15 @@ class Conductor
    */
   public static function forceBPM(?bpm:Float = null)
   {
-    if (bpm != null) trace('[CONDUCTOR] Forcing BPM to ' + bpm);
+    if (bpm != null)
+    {
+      trace('[CONDUCTOR] Forcing BPM to ${bpm}');
+    }
     else
-      trace('[CONDUCTOR] Resetting BPM to default');
+    {
+      // trace('[CONDUCTOR] Resetting BPM to default');
+    }
+
     Conductor.bpmOverride = bpm;
   }
 
@@ -272,9 +278,9 @@ class Conductor
           if (currentTimeChange.timeStamp > 0.0 && timeChanges.length > 0)
           {
             var prevTimeChange:SongTimeChange = timeChanges[timeChanges.length - 1];
-            currentTimeChange.beatTime = prevTimeChange.beatTime
-              + ((currentTimeChange.timeStamp - prevTimeChange.timeStamp) * prevTimeChange.bpm / Constants.SECS_PER_MIN / Constants.MS_PER_SEC)
-              + 0.01;
+            currentTimeChange.beatTime = FlxMath.roundDecimal(prevTimeChange.beatTime
+              + ((currentTimeChange.timeStamp - prevTimeChange.timeStamp) * prevTimeChange.bpm / Constants.SECS_PER_MIN / Constants.MS_PER_SEC),
+              4);
           }
         }
       }
@@ -282,7 +288,10 @@ class Conductor
       timeChanges.push(currentTimeChange);
     }
 
-    trace('Done mapping time changes: ' + timeChanges);
+    if (timeChanges.length > 0)
+    {
+      trace('Done mapping time changes: ${timeChanges}' + timeChanges);
+    }
 
     // Update currentStepTime
     Conductor.update(Conductor.songPosition);
diff --git a/source/funkin/Controls.hx b/source/funkin/Controls.hx
index e8a66cb14..81055fb34 100644
--- a/source/funkin/Controls.hx
+++ b/source/funkin/Controls.hx
@@ -50,7 +50,7 @@ enum Control
   #end
 }
 
-@:enum
+enum
 abstract Action(String) to String from String
 {
   var UI_UP = "ui_up";
diff --git a/source/funkin/FreeplayState.hx b/source/funkin/FreeplayState.hx
index 9ad27bfcc..dd87e7d36 100644
--- a/source/funkin/FreeplayState.hx
+++ b/source/funkin/FreeplayState.hx
@@ -492,22 +492,6 @@ class FreeplayState extends MusicBeatSubState
       }
     }
 
-    // if (regexp != null)
-    // 	tempSongs = songs.filter(item -> regexp.match(item.songName));
-
-    // tempSongs.sort(function(a, b):Int
-    // {
-    // 	var tempA = a.songName.toUpperCase();
-    // 	var tempB = b.songName.toUpperCase();
-
-    // 	if (tempA < tempB)
-    // 		return -1;
-    // 	else if (tempA > tempB)
-    // 		return 1;
-    // 	else
-    // 		return 0;
-    // });
-
     for (i in 0...tempSongs.length)
     {
       var funnyMenu:SongMenuItem = new SongMenuItem(FlxG.width, (i * 150) + 160, tempSongs[i].songName);
diff --git a/source/funkin/data/BaseRegistry.hx b/source/funkin/data/BaseRegistry.hx
index 36b1d26e3..98393fda4 100644
--- a/source/funkin/data/BaseRegistry.hx
+++ b/source/funkin/data/BaseRegistry.hx
@@ -2,6 +2,7 @@ package funkin.data;
 
 import openfl.Assets;
 import funkin.util.assets.DataAssets;
+import funkin.util.VersionUtil;
 import haxe.Constraints.Constructible;
 
 /**
@@ -24,16 +25,23 @@ abstract class BaseRegistry<T:(IRegistryEntry<J> & Constructible<EntryConstructo
 
   final entries:Map<String, T>;
 
+  /**
+   * The version rule to use when loading entries.
+   * If the entry's version does not match this rule, migration is needed.
+   */
+  final versionRule:thx.semver.VersionRule;
+
   // public abstract static final instance:BaseRegistry<T, J> = new BaseRegistry<>();
 
   /**
    * @param registryId A readable ID for this registry, used when logging.
    * @param dataFilePath The path (relative to `assets/data`) to search for JSON files.
    */
-  public function new(registryId:String, dataFilePath:String)
+  public function new(registryId:String, dataFilePath:String, versionRule:thx.semver.VersionRule = null)
   {
     this.registryId = registryId;
     this.dataFilePath = dataFilePath;
+    this.versionRule = versionRule == null ? "1.0.x" : versionRule;
 
     this.entries = new Map<String, T>();
   }
@@ -125,6 +133,13 @@ abstract class BaseRegistry<T:(IRegistryEntry<J> & Constructible<EntryConstructo
     return 'Registry(' + registryId + ', ${countEntries()} entries)';
   }
 
+  public function fetchEntryVersion(id:String):Null<thx.semver.Version>
+  {
+    var entryStr:String = loadEntryFile(id);
+    var entryVersion:thx.semver.Version = VersionUtil.getVersionFromJSON(entryStr);
+    return entryVersion;
+  }
+
   function log(message:String):Void
   {
     trace('[' + registryId + '] ' + message);
@@ -154,10 +169,36 @@ abstract class BaseRegistry<T:(IRegistryEntry<J> & Constructible<EntryConstructo
   /**
    * Read, parse, and validate the JSON data and produce the corresponding data object.
    *
-   * NOTE: Must be implemented on the implementation class annd
+   * NOTE: Must be implemented on the implementation class.
    */
   public abstract function parseEntryData(id:String):Null<J>;
 
+  /**
+   * Read, parse, and validate the JSON data and produce the corresponding data object,
+   * accounting for old versions of the data.
+   *
+   * NOTE: Extend this function to handle migration.
+   */
+  public function parseEntryDataWithMigration(id:String, version:thx.semver.Version):Null<J>
+  {
+    // If a version rule is not specified, do not check against it.
+    if (versionRule == null || VersionUtil.validateVersion(version, versionRule))
+    {
+      return parseEntryData(id);
+    }
+    else
+    {
+      throw '[${registryId}] Entry ${id} does not support migration.';
+    }
+
+    // Example:
+    // if (VersionUtil.validateVersion(version, "0.1.x")) {
+    //   return parseEntryData_v0_1_x(id);
+    // } else {
+    //   super.parseEntryDataWithMigration(id, version);
+    // }
+  }
+
   /**
    * Retrieve the list of scripted class names to load.
    * @return An array of scripted class names.
diff --git a/source/funkin/data/level/LevelRegistry.hx b/source/funkin/data/level/LevelRegistry.hx
index 54ed81093..36ce883ea 100644
--- a/source/funkin/data/level/LevelRegistry.hx
+++ b/source/funkin/data/level/LevelRegistry.hx
@@ -11,13 +11,15 @@ class LevelRegistry extends BaseRegistry<Level, LevelData>
    * Handle breaking changes by incrementing this value
    * and adding migration to the `migrateStageData()` function.
    */
-  public static final LEVEL_DATA_VERSION:String = "1.0.0";
+  public static final LEVEL_DATA_VERSION:thx.semver.Version = "1.0.0";
+
+  public static final LEVEL_DATA_VERSION_RULE:thx.semver.VersionRule = "1.0.x";
 
   public static final instance:LevelRegistry = new LevelRegistry();
 
   public function new()
   {
-    super('LEVEL', 'levels');
+    super('LEVEL', 'levels', LEVEL_DATA_VERSION_RULE);
   }
 
   /**
@@ -34,7 +36,7 @@ class LevelRegistry extends BaseRegistry<Level, LevelData>
 
     if (parser.errors.length > 0)
     {
-      trace('Failed to parse entry data: ${id}');
+      trace('[${registryId}] Failed to parse entry data: ${id}');
       for (error in parser.errors)
       {
         trace(error);
diff --git a/source/funkin/data/notestyle/NoteStyleRegistry.hx b/source/funkin/data/notestyle/NoteStyleRegistry.hx
index d666a037c..65f6f627a 100644
--- a/source/funkin/data/notestyle/NoteStyleRegistry.hx
+++ b/source/funkin/data/notestyle/NoteStyleRegistry.hx
@@ -11,7 +11,9 @@ class NoteStyleRegistry extends BaseRegistry<NoteStyle, NoteStyleData>
    * Handle breaking changes by incrementing this value
    * and adding migration to the `migrateNoteStyleData()` function.
    */
-  public static final NOTE_STYLE_DATA_VERSION:String = "1.0.0";
+  public static final NOTE_STYLE_DATA_VERSION:thx.semver.Version = "1.0.0";
+
+  public static final NOTE_STYLE_DATA_VERSION_RULE:thx.semver.VersionRule = "1.0.x";
 
   public static final DEFAULT_NOTE_STYLE_ID:String = "funkin";
 
@@ -19,7 +21,7 @@ class NoteStyleRegistry extends BaseRegistry<NoteStyle, NoteStyleData>
 
   public function new()
   {
-    super('NOTESTYLE', 'notestyles');
+    super('NOTESTYLE', 'notestyles', NOTE_STYLE_DATA_VERSION_RULE);
   }
 
   public function fetchDefault():NoteStyle
@@ -43,7 +45,7 @@ class NoteStyleRegistry extends BaseRegistry<NoteStyle, NoteStyleData>
 
     if (parser.errors.length > 0)
     {
-      trace('Failed to parse entry data: ${id}');
+      trace('[${registryId}] Failed to parse entry data: ${id}');
       for (error in parser.errors)
       {
         trace(error);
diff --git a/source/funkin/freeplayStuff/DJBoyfriend.hx b/source/funkin/freeplayStuff/DJBoyfriend.hx
index b109fb03f..5bee4129a 100644
--- a/source/funkin/freeplayStuff/DJBoyfriend.hx
+++ b/source/funkin/freeplayStuff/DJBoyfriend.hx
@@ -40,27 +40,6 @@ class DJBoyfriend extends FlxSprite
   {
     super.update(elapsed);
 
-    if (FlxG.keys.justPressed.LEFT)
-    {
-      animOffsets["confirm"] = [animOffsets["confirm"][0] + 1, animOffsets["confirm"][1]];
-      applyAnimOffset();
-    }
-    else if (FlxG.keys.justPressed.RIGHT)
-    {
-      animOffsets["confirm"] = [animOffsets["confirm"][0] - 1, animOffsets["confirm"][1]];
-      applyAnimOffset();
-    }
-    else if (FlxG.keys.justPressed.UP)
-    {
-      animOffsets["confirm"] = [animOffsets["confirm"][0], animOffsets["confirm"][1] + 1];
-      applyAnimOffset();
-    }
-    else if (FlxG.keys.justPressed.DOWN)
-    {
-      animOffsets["confirm"] = [animOffsets["confirm"][0], animOffsets["confirm"][1] - 1];
-      applyAnimOffset();
-    }
-
     switch (currentState)
     {
       case Intro:
diff --git a/source/funkin/freeplayStuff/SongMenuItem.hx b/source/funkin/freeplayStuff/SongMenuItem.hx
index 3d9f9dd04..37198f6d7 100644
--- a/source/funkin/freeplayStuff/SongMenuItem.hx
+++ b/source/funkin/freeplayStuff/SongMenuItem.hx
@@ -103,9 +103,6 @@ class SongMenuItem extends FlxSpriteGroup
       y = CoolUtil.coolLerp(y, targetPos.y, 0.4);
     }
 
-    if (FlxG.keys.justPressed.ALT) selected = false;
-    if (FlxG.keys.justPressed.CONTROL) selected = true;
-
     super.update(elapsed);
   }
 
diff --git a/source/funkin/modding/PolymodHandler.hx b/source/funkin/modding/PolymodHandler.hx
index 1ff2c0caa..3f5752acc 100644
--- a/source/funkin/modding/PolymodHandler.hx
+++ b/source/funkin/modding/PolymodHandler.hx
@@ -24,7 +24,7 @@ class PolymodHandler
    * Bug fixes increment the patch version, new features increment the minor version.
    * Changes that break old mods increment the major version.
    */
-  static final API_VERSION = "0.1.0";
+  static final API_VERSION:String = "0.1.0";
 
   /**
    * Where relative to the executable that mods are located.
diff --git a/source/funkin/modding/module/ModuleHandler.hx b/source/funkin/modding/module/ModuleHandler.hx
index 5a1c4dd6a..3cc7b7984 100644
--- a/source/funkin/modding/module/ModuleHandler.hx
+++ b/source/funkin/modding/module/ModuleHandler.hx
@@ -67,19 +67,26 @@ class ModuleHandler
   {
     modulePriorityOrder = moduleCache.keys().array();
 
-    modulePriorityOrder.sort(function(a:String, b:String):Int {
-      var aModule:Module = moduleCache.get(a);
-      var bModule:Module = moduleCache.get(b);
+    modulePriorityOrder.sort(sortByPriority);
+  }
 
-      if (aModule.priority != bModule.priority)
-      {
-        return aModule.priority - bModule.priority;
-      }
-      else
-      {
-        return SortUtil.alphabetically(a, b);
-      }
-    });
+  /**
+   * Given two module IDs, sort them by priority.
+   * @return 1 or -1 depending on which module has a higher priority.
+   */
+  static function sortByPriority(a:String, b:String)
+  {
+    var aModule:Module = moduleCache.get(a);
+    var bModule:Module = moduleCache.get(b);
+
+    if (aModule.priority != bModule.priority)
+    {
+      return aModule.priority - bModule.priority;
+    }
+    else
+    {
+      return SortUtil.alphabetically(a, b);
+    }
   }
 
   public static function getModule(moduleId:String):Module
diff --git a/source/funkin/play/HealthIcon.hx b/source/funkin/play/HealthIcon.hx
index e4802b99c..7785fb4b1 100644
--- a/source/funkin/play/HealthIcon.hx
+++ b/source/funkin/play/HealthIcon.hx
@@ -146,13 +146,13 @@ class HealthIcon extends FlxSprite
    */
   public function toggleOldIcon():Void
   {
-    if (characterId == 'beta')
+    if (characterId == 'bf-old')
     {
       characterId = PlayState.instance.currentPlayerId;
     }
     else
     {
-      characterId = 'beta';
+      characterId = 'bf-old';
     }
   }
 
diff --git a/source/funkin/play/PlayState.hx b/source/funkin/play/PlayState.hx
index a28c35c67..d01c7b049 100644
--- a/source/funkin/play/PlayState.hx
+++ b/source/funkin/play/PlayState.hx
@@ -666,14 +666,6 @@ class PlayState extends MusicBeatSubState
 
     super.update(elapsed);
 
-    if (FlxG.keys.justPressed.U)
-    {
-      // hack for HaxeUI generation, doesn't work unless persistentUpdate is false at state creation!!
-      disableKeys = true;
-      persistentUpdate = false;
-      openSubState(new StageOffsetSubState());
-    }
-
     updateHealthBar();
     updateScoreText();
 
diff --git a/source/funkin/play/character/CharacterData.hx b/source/funkin/play/character/CharacterData.hx
index 18a537a40..710eb884b 100644
--- a/source/funkin/play/character/CharacterData.hx
+++ b/source/funkin/play/character/CharacterData.hx
@@ -382,7 +382,7 @@ class CharacterDataParser
       input.version = CHARACTER_DATA_VERSION;
     }
 
-    if (!VersionUtil.validateVersion(input.version, CHARACTER_DATA_VERSION_RULE))
+    if (!VersionUtil.validateVersionStr(input.version, CHARACTER_DATA_VERSION_RULE))
     {
       trace('ERROR: Could not load character data for "$id": bad version (got ${input.version}, expected ${CHARACTER_DATA_VERSION_RULE})');
       return null;
diff --git a/source/funkin/play/cutscene/dialogue/Conversation.hx b/source/funkin/play/cutscene/dialogue/Conversation.hx
index 0816e1d25..a6851f0f9 100644
--- a/source/funkin/play/cutscene/dialogue/Conversation.hx
+++ b/source/funkin/play/cutscene/dialogue/Conversation.hx
@@ -5,7 +5,7 @@ import flixel.group.FlxSpriteGroup;
 import flixel.util.FlxColor;
 import flixel.tweens.FlxTween;
 import flixel.tweens.FlxEase;
-import flixel.system.FlxSound;
+import flixel.sound.FlxSound;
 import funkin.util.SortUtil;
 import flixel.util.FlxSort;
 import funkin.modding.events.ScriptEvent;
@@ -18,7 +18,7 @@ import flixel.addons.display.FlxPieDial;
 
 /**
  * A high-level handler for dialogue.
- * 
+ *
  * This shit is great for modders but it's pretty elaborate for how much it'll actually be used, lolol. -Eric
  */
 class Conversation extends FlxSpriteGroup implements IDialogueScriptedClass
@@ -299,7 +299,7 @@ class Conversation extends FlxSpriteGroup implements IDialogueScriptedClass
   /**
    * Dispatch an event to attempt to advance the conversation.
    * This is done once at the start of the conversation, and once whenever the user presses CONFIRM to advance the conversation.
-   * 
+   *
    * The broadcast event may be cancelled by modules or ScriptedConversations. This will prevent the conversation from actually advancing.
    * This is useful if you want to manually play an animation or something.
    */
@@ -365,7 +365,7 @@ class Conversation extends FlxSpriteGroup implements IDialogueScriptedClass
 
   /**
    * Dispatch an event to attempt to immediately end the conversation.
-   * 
+   *
    * The broadcast event may be cancelled by modules or ScriptedConversations. This will prevent the conversation from being cancelled.
    * This is useful if you want to prevent an animation from being skipped or something.
    */
@@ -567,7 +567,7 @@ class Conversation extends FlxSpriteGroup implements IDialogueScriptedClass
 
   /**
    * As this event is dispatched to the Conversation, it is also dispatched to the active speaker.
-   * @param event 
+   * @param event
    */
   function propagateEvent(event:ScriptEvent):Void
   {
diff --git a/source/funkin/play/notes/notestyle/NoteStyle.hx b/source/funkin/play/notes/notestyle/NoteStyle.hx
index 6cb9e7cdc..fd45342a0 100644
--- a/source/funkin/play/notes/notestyle/NoteStyle.hx
+++ b/source/funkin/play/notes/notestyle/NoteStyle.hx
@@ -104,6 +104,10 @@ class NoteStyle implements IRegistryEntry<NoteStyleData>
 
     noteFrames = Paths.getSparrowAtlas(getNoteAssetPath(), getNoteAssetLibrary());
 
+    if (noteFrames == null) {
+      throw 'Could not load note frames for note style: $id';
+    }
+
     noteFrames.parent.persist = true;
 
     return noteFrames;
@@ -161,7 +165,8 @@ class NoteStyle implements IRegistryEntry<NoteStyleData>
   {
     if (raw)
     {
-      var rawPath:Null<String> = _data?.assets?.holdNote?.assetPath;
+      // TODO: figure out why ?. didn't work here
+      var rawPath:Null<String> = (_data?.assets?.holdNote == null) ? null : _data?.assets?.holdNote?.assetPath;
       return (rawPath == null) ? fallback.getHoldNoteAssetPath(true) : rawPath;
     }
 
@@ -299,6 +304,6 @@ class NoteStyle implements IRegistryEntry<NoteStyleData>
 
   public function _fetchData(id:String):Null<NoteStyleData>
   {
-    return NoteStyleRegistry.instance.parseEntryData(id);
+    return NoteStyleRegistry.instance.parseEntryDataWithMigration(id, NoteStyleRegistry.instance.fetchEntryVersion(id));
   }
 }
diff --git a/source/funkin/play/song/SongMigrator.hx b/source/funkin/play/song/SongMigrator.hx
index f561c4d3e..bb8718bb7 100644
--- a/source/funkin/play/song/SongMigrator.hx
+++ b/source/funkin/play/song/SongMigrator.hx
@@ -32,7 +32,7 @@ class SongMigrator
   {
     if (jsonData.version != null)
     {
-      if (VersionUtil.validateVersion(jsonData.version, CHART_VERSION_RULE))
+      if (VersionUtil.validateVersionStr(jsonData.version, CHART_VERSION_RULE))
       {
         trace('Song (${songId}) metadata version (${jsonData.version}) is valid and up-to-date.');
 
@@ -70,7 +70,7 @@ class SongMigrator
   {
     if (jsonData.version)
     {
-      if (VersionUtil.validateVersion(jsonData.version, CHART_VERSION_RULE))
+      if (VersionUtil.validateVersionStr(jsonData.version, CHART_VERSION_RULE))
       {
         trace('Song (${songId}) chart version (${jsonData.version}) is valid and up-to-date.');
 
diff --git a/source/funkin/play/stage/StageData.hx b/source/funkin/play/stage/StageData.hx
index de8804cfb..867c6e1a5 100644
--- a/source/funkin/play/stage/StageData.hx
+++ b/source/funkin/play/stage/StageData.hx
@@ -217,7 +217,7 @@ class StageDataParser
       return null;
     }
 
-    if (!VersionUtil.validateVersion(input.version, STAGE_DATA_VERSION_RULE))
+    if (!VersionUtil.validateVersionStr(input.version, STAGE_DATA_VERSION_RULE))
     {
       trace('ERROR: Could not load stage data for "$id": bad version (got ${input.version}, expected ${STAGE_DATA_VERSION_RULE})');
       return null;
diff --git a/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx b/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx
index 43e8ac96c..df5a25b62 100644
--- a/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx
+++ b/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx
@@ -257,6 +257,7 @@ class ChartEditorDialogHandler
    * @param closable Whether the dialog can be closed by the user.
    * @return The dialog that was opened.
    */
+  @:haxe.warning("-WVarInit")
   public static function openUploadInstDialog(state:ChartEditorState, ?closable:Bool = true):Dialog
   {
     var dialog:Dialog = openDialog(state, CHART_EDITOR_DIALOG_UPLOAD_INST_LAYOUT, true, closable);
@@ -416,6 +417,7 @@ class ChartEditorDialogHandler
    * @param state The ChartEditorState instance.
    * @return The dialog to open.
    */
+  @:haxe.warning("-WVarInit")
   public static function openSongMetadataDialog(state:ChartEditorState):Dialog
   {
     var dialog:Dialog = openDialog(state, CHART_EDITOR_DIALOG_SONG_METADATA_LAYOUT, true, false);
diff --git a/source/funkin/ui/debug/charting/ChartEditorEventSprite.hx b/source/funkin/ui/debug/charting/ChartEditorEventSprite.hx
index 768e0be52..2cd9ab2fe 100644
--- a/source/funkin/ui/debug/charting/ChartEditorEventSprite.hx
+++ b/source/funkin/ui/debug/charting/ChartEditorEventSprite.hx
@@ -95,7 +95,7 @@ class ChartEditorEventSprite extends FlxSprite
   public function correctAnimationName(name:String):String
   {
     if (this.animation.exists(name)) return name;
-    trace('Warning: Invalid animation name "' + name + '" for song event. Using "${DEFAULT_EVENT}"');
+    trace('Warning: Invalid animation name "${name}" for song event. Using "${DEFAULT_EVENT}"');
     return DEFAULT_EVENT;
   }
 
diff --git a/source/funkin/ui/debug/charting/ChartEditorState.hx b/source/funkin/ui/debug/charting/ChartEditorState.hx
index e1ed75b06..aa6e70714 100644
--- a/source/funkin/ui/debug/charting/ChartEditorState.hx
+++ b/source/funkin/ui/debug/charting/ChartEditorState.hx
@@ -15,7 +15,7 @@ import flixel.addons.transition.FlxTransitionableState;
 import flixel.input.keyboard.FlxKey;
 import flixel.math.FlxPoint;
 import flixel.math.FlxRect;
-import flixel.system.FlxSound;
+import flixel.sound.FlxSound;
 import flixel.tweens.FlxEase;
 import flixel.tweens.FlxTween;
 import flixel.tweens.misc.VarTween;
diff --git a/source/funkin/ui/story/Level.hx b/source/funkin/ui/story/Level.hx
index 7913ac8ca..1e5d60bf3 100644
--- a/source/funkin/ui/story/Level.hx
+++ b/source/funkin/ui/story/Level.hx
@@ -181,6 +181,6 @@ class Level implements IRegistryEntry<LevelData>
 
   public function _fetchData(id:String):Null<LevelData>
   {
-    return LevelRegistry.instance.parseEntryData(id);
+    return LevelRegistry.instance.parseEntryDataWithMigration(id, LevelRegistry.instance.fetchEntryVersion(id));
   }
 }
diff --git a/source/funkin/util/BezierUtil.hx b/source/funkin/util/BezierUtil.hx
index 56d20cf48..b3cf51d1d 100644
--- a/source/funkin/util/BezierUtil.hx
+++ b/source/funkin/util/BezierUtil.hx
@@ -15,7 +15,7 @@ class BezierUtil
 
   /**
    * Linearly interpolate between three values.
-   * Depending on p, 0 = a, 0.5 = b, 1 = c, 0.25 = halfway between a and c, etc.
+   * Depending on p, 0 = a, 0.5 = b, 1 = c, 0.25 = halfway between a and b, etc.
    */
   static inline function mix3(p:Float, a:Float, b:Float, c:Float):Float
   {
@@ -32,11 +32,6 @@ class BezierUtil
     return mix2(p, mix4(p, a, b, c, d), mix4(p, b, c, d, e));
   }
 
-  static inline function mix6(p:Float, a:Float, b:Float, c:Float, d:Float, e:Float, f:Float):Float
-  {
-    return mix2(p, mix5(p, a, b, c, d, e), mix5(p, b, c, d, e, f));
-  }
-
   /**
    * A bezier curve with two points.
    * This is really just linear interpolation but whatever.
diff --git a/source/funkin/util/Constants.hx b/source/funkin/util/Constants.hx
index c06911e4e..71cfe7b8e 100644
--- a/source/funkin/util/Constants.hx
+++ b/source/funkin/util/Constants.hx
@@ -88,12 +88,17 @@ class Constants
   public static final COLOR_HEALTH_BAR_GREEN:FlxColor = 0xFF66FF33;
 
   /**
-   * The base colors of the notes.
+   * The base colors used by notes.
    */
-  public static final COLOR_NOTES:Array<FlxColor> = [0xFFFF22AA, 0xFF00EEFF, 0xFF00CC00, 0xFFCC1111];
+  public static var COLOR_NOTES:Array<FlxColor> = [
+    0xFFFF22AA, // left (0)
+    0xFF00EEFF, // down (1)
+    0xFF00CC00, // up (2)
+    0xFFCC1111 // right (3)
+  ];
 
   /**
-   * STAGE DEFAULTS
+   * GAME DEFAULTS
    */
   // ==============================
 
diff --git a/source/funkin/util/DateUtil.hx b/source/funkin/util/DateUtil.hx
index 715371f80..72838477c 100644
--- a/source/funkin/util/DateUtil.hx
+++ b/source/funkin/util/DateUtil.hx
@@ -2,9 +2,10 @@ package funkin.util;
 
 class DateUtil
 {
-  public static function generateTimestamp():String
+  public static function generateTimestamp(?date:Date = null):String
   {
-    var date = Date.now();
+    if (date == null) date = Date.now();
+
     return
       '${date.getFullYear()}-${Std.string(date.getMonth() + 1).lpad('0', 2)}-${Std.string(date.getDate()).lpad('0', 2)}-${Std.string(date.getHours()).lpad('0', 2)}-${Std.string(date.getMinutes()).lpad('0', 2)}-${Std.string(date.getSeconds()).lpad('0', 2)}';
   }
diff --git a/source/funkin/util/SaveDataUtil.hx b/source/funkin/util/SaveDataUtil.hx
deleted file mode 100644
index 202536aad..000000000
--- a/source/funkin/util/SaveDataUtil.hx
+++ /dev/null
@@ -1 +0,0 @@
-package funkin.util;
diff --git a/source/funkin/util/SerializerUtil.hx b/source/funkin/util/SerializerUtil.hx
index d731aee8f..0075e83c0 100644
--- a/source/funkin/util/SerializerUtil.hx
+++ b/source/funkin/util/SerializerUtil.hx
@@ -11,26 +11,21 @@ typedef ScoreInput =
   var t:Int; // Start timestamp
 }
 
+/**
+ * A class of functions dedicated to serializing and deserializing data.
+ */
 class SerializerUtil
 {
   static final INDENT_CHAR = "\t";
 
   /**
    * Convert a Haxe object to a JSON string.
-  **/
+   */
   public static function toJSON(input:Dynamic, ?pretty:Bool = true):String
   {
     return Json.stringify(input, replacer, pretty ? INDENT_CHAR : null);
   }
 
-  /**
-   * Convert a JSON string to a Haxe object of the chosen type.
-   */
-  public static function fromJSONTyped<T>(input:String, type:Class<T>):T
-  {
-    return cast Json.parse(input);
-  }
-
   /**
    * Convert a JSON string to a Haxe object.
    */
@@ -76,14 +71,19 @@ class SerializerUtil
       if (Std.isOfType(value, String)) return value;
 
       // Stringify Version objects.
-      var valueVersion:thx.semver.Version = cast value;
-      var result = '${valueVersion.major}.${valueVersion.minor}.${valueVersion.patch}';
-      if (valueVersion.hasPre) result += '-${valueVersion.pre}';
-      if (valueVersion.hasBuild) result += '+${valueVersion.build}';
-      return result;
+      return serializeVersion(cast value);
     }
 
     // Else, return the value as-is.
     return value;
   }
+
+  static inline function serializeVersion(value:thx.semver.Version):String
+  {
+    var result = '${value.major}.${value.minor}.${value.patch}';
+    if (value.hasPre) result += '-${value.pre}';
+    // TODO: Merge fix for version.hasBuild
+    if (value.build.length > 0) result += '+${value.build}';
+    return result;
+  }
 }
diff --git a/source/funkin/util/VersionUtil.hx b/source/funkin/util/VersionUtil.hx
index 08cde69a6..368bb12de 100644
--- a/source/funkin/util/VersionUtil.hx
+++ b/source/funkin/util/VersionUtil.hx
@@ -14,13 +14,11 @@ class VersionUtil
    * Checks that a given verison number satisisfies a given version rule.
    * Version rule can be complex, e.g. "1.0.x" or ">=1.0.0,<1.1.0", or anything NPM supports.
    */
-  public static function validateVersion(version:String, versionRule:String):Bool
+  public static function validateVersion(version:thx.semver.Version, versionRule:thx.semver.VersionRule):Bool
   {
     try
     {
-      var v:Version = version; // Perform a cast.
-      var vr:VersionRule = versionRule; // Perform a cast.
-      return v.satisfies(vr);
+      return version.satisfies(versionRule);
     }
     catch (e)
     {
@@ -28,4 +26,38 @@ class VersionUtil
       return false;
     }
   }
+
+  /**
+   * Checks that a given verison number satisisfies a given version rule.
+   * Version rule can be complex, e.g. "1.0.x" or ">=1.0.0,<1.1.0", or anything NPM supports.
+   */
+  public static function validateVersionStr(version:String, versionRule:String):Bool
+  {
+    try
+    {
+      var version:thx.semver.Version = version;
+      var versionRule:thx.semver.VersionRule = versionRule;
+      return version.satisfies(versionRule);
+    }
+    catch (e)
+    {
+      trace('[VERSIONUTIL] Invalid semantic version: ${version}');
+      return false;
+    }
+  }
+
+  /**
+   * Get and parse the semantic version from a JSON string.
+   * @param input The JSON string to parse.
+   * @return The semantic version, or null if it could not be parsed.
+   */
+  public static function getVersionFromJSON(input:String):Null<thx.semver.Version>
+  {
+    var parsed = SerializerUtil.fromJSON(input);
+    if (parsed == null) return null;
+    if (parsed.version == null) return null;
+    var versionStr:String = parsed.version; // Dynamic -> String cast
+    var version:thx.semver.Version = versionStr; // Implicit, not explicit, cast.
+    return version;
+  }
 }
diff --git a/source/funkin/util/assets/FlxAnimationUtil.hx b/source/funkin/util/assets/FlxAnimationUtil.hx
index 0e32a1918..f94dc4dc3 100644
--- a/source/funkin/util/assets/FlxAnimationUtil.hx
+++ b/source/funkin/util/assets/FlxAnimationUtil.hx
@@ -19,7 +19,7 @@ class FlxAnimationUtil
     if (anim.frameIndices != null && anim.frameIndices.length > 0)
     {
       // trace('addByIndices(${anim.name}, ${anim.prefix}, ${anim.frameIndices}, ${frameRate}, ${looped}, ${flipX}, ${flipY})');
-      target.animation.addByIndices(anim.name, anim.prefix, anim.frameIndices, "", frameRate, looped, flipX, flipY);
+      target.animation.addByIndices(anim.name, anim.prefix, anim.frameIndices, '', frameRate, looped, flipX, flipY);
       // trace('RESULT:${target.animation.getAnimationList()}');
     }
     else
diff --git a/source/funkin/util/tools/ArraySortTools.hx b/source/funkin/util/tools/ArraySortTools.hx
index 3af114b98..9a3f8b349 100644
--- a/source/funkin/util/tools/ArraySortTools.hx
+++ b/source/funkin/util/tools/ArraySortTools.hx
@@ -108,6 +108,9 @@ class ArraySortTools
       input[i] = input[j];
       input[j] = temp;
     }
+
+    // Don't expect to get here.
+    return -1;
   }
 
   /**
diff --git a/source/funkin/util/tools/MapTools.hx b/source/funkin/util/tools/MapTools.hx
index 461b88bbf..739c5efdb 100644
--- a/source/funkin/util/tools/MapTools.hx
+++ b/source/funkin/util/tools/MapTools.hx
@@ -27,6 +27,7 @@ class MapTools
 
   /**
    * Return a list of keys from the map (as an array, rather than an iterator).
+   * TODO: Rename this?
    */
   public static function keyValues<K, T>(map:Map<K, T>):Array<K>
   {
diff --git a/source/funkin/util/tools/StringTools.hx b/source/funkin/util/tools/StringTools.hx
index 8ff76a080..0585ffeae 100644
--- a/source/funkin/util/tools/StringTools.hx
+++ b/source/funkin/util/tools/StringTools.hx
@@ -51,6 +51,7 @@ class StringTools
 
   /**
    * Parses the string data as JSON and returns the resulting object.
+   * This is here so you can use `string.parseJSON()` when `using StringTools`.
    *
    * @return The parsed object.
    */
diff --git a/tests/unit/.gitignore b/tests/unit/.gitignore
new file mode 100644
index 000000000..abb6c9cf9
--- /dev/null
+++ b/tests/unit/.gitignore
@@ -0,0 +1,7 @@
+
+bin/
+# auto-generated
+source/TestSuite.hx
+.temp/
+report/
+build/
diff --git a/tests/unit/.munit b/tests/unit/.munit
new file mode 100644
index 000000000..61de57963
--- /dev/null
+++ b/tests/unit/.munit
@@ -0,0 +1,7 @@
+version=2.3.5
+src=source
+bin=bin
+report=report
+hxml=test.hxml
+classPaths=../../source
+coveragePackages=funkin
diff --git a/tests/unit/.vscode/launch.json b/tests/unit/.vscode/launch.json
new file mode 100644
index 000000000..a255f1644
--- /dev/null
+++ b/tests/unit/.vscode/launch.json
@@ -0,0 +1,13 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Lime",
+            "type": "lime",
+            "request": "launch"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/tests/unit/README.md b/tests/unit/README.md
new file mode 100644
index 000000000..00fed78e5
--- /dev/null
+++ b/tests/unit/README.md
@@ -0,0 +1,50 @@
+Flixel Unit Tests
+-----------------
+
+This is a unit test project using [munit](https://github.com/massiveinteractive/MassiveUnit). It's good practice to add tests for fixed bugs or new features.
+
+TODO Make sure the unit tests are automatically run on GitHub Actions.
+
+There's a 1:1 mapping between `.hx` files in `source/` and the unit test project - tests for `funkin.Conductor` go into `funkin.ConductorTest` etc.
+
+### Building
+
+Run one of the `test-*.hxml` files in this directory to run the tests on that specific target, e.g. `haxe test-cpp.hxml`. Currently supported are:
+
+- `web` (HTML5)
+- `cpp` (Native)
+
+Alternatively, this can be done from within Visual Studio Code - (`F1` -> `Tasks: Run Task` -> Choose the target to test).
+
+#### Adding Tests
+
+- Run `haxelib run munit create com.FooBarTest -for com.Foo`
+- Use `@:allow(full.package.name.ClassName)` to allow a test class to call private functions.
+- Use `mockatoo.Mockatoo.mock(ClassName)` to mock a class. See [Mockatoo docs](https://github.com/misprintt/mockatoo).
+
+#### Functions
+
+- `@Before` functions are named `before()`
+- Each `@Test` function starts with `test` and describes what exactly it tests. This can lead to long function names like `FlxEmitter#testStartShouldNotReviveMembers()` and serves as self-documentation.
+- Another thing that helps with self-documentation is adding a comment for tests that are related an issue on GitHub.
+
+	```haxe
+	@Test // #1203
+	function testColorWithAlphaComparison()
+	```
+
+### `FunkinTest` base class
+
+Test classes extend `FunkinTest`, which is a base class with some utility functions for testing.
+
+### `step()`
+
+`step()` advances the `FlxGame` exactly one step. This is useful for tests that depend on game time advancing / `FlxGame#step()` being executed, such as physics of `add()`ed objects, state switches, or just time passing for tweens or timers.
+
+There are two parameters:
+- `steps` - specifies the amount of steps to advance (defaults to 1)
+- `callback` - an optional callback function that is executed after each step
+
+### `testDestroy()`
+
+`testDestroy()` tests whether an `IFlxDestroyable` can safely be `destroy()`ed more than once (null reference errors are fairly common here). For this, `destroyable` has to be set during `before()` of the test class.
diff --git a/tests/unit/assets/preload/data/anotherFile.txt b/tests/unit/assets/preload/data/anotherFile.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/assets/preload/data/levels/test.json b/tests/unit/assets/preload/data/levels/test.json
new file mode 100644
index 000000000..8b004e213
--- /dev/null
+++ b/tests/unit/assets/preload/data/levels/test.json
@@ -0,0 +1,47 @@
+{
+  "version": "1.0.0",
+  "name": "TEACHING TIME",
+  "titleAsset": "storymenu/titles/tutorial",
+  "props": [
+    {
+      "assetPath": "storymenu/props/gf",
+      "scale": 1.0,
+      "danceEvery": 2,
+      "offsets": [80, 80],
+      "animations": [
+        {
+          "name": "danceLeft",
+          "prefix": "idle0",
+          "frameIndices": [30, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
+        },
+        {
+          "name": "danceRight",
+          "prefix": "idle0",
+          "frameIndices": [
+            15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29
+          ]
+        }
+      ]
+    },
+    {
+      "assetPath": "storymenu/props/bf",
+      "scale": 1.0,
+      "danceEvery": 2,
+      "offsets": [150, 80],
+      "animations": [
+        {
+          "name": "idle",
+          "prefix": "idle0",
+          "frameRate": 24
+        },
+        {
+          "name": "confirm",
+          "prefix": "confirm0",
+          "frameRate": 24
+        }
+      ]
+    }
+  ],
+  "background": "#F9CF51",
+  "songs": ["tutorial"]
+}
diff --git a/tests/unit/assets/preload/data/mytype/blablabla.json b/tests/unit/assets/preload/data/mytype/blablabla.json
new file mode 100644
index 000000000..cf7d16746
--- /dev/null
+++ b/tests/unit/assets/preload/data/mytype/blablabla.json
@@ -0,0 +1,6 @@
+{
+  "version": "1.0.0",
+  "id": "blablabla",
+  "name": "blablabla API",
+  "data": []
+}
diff --git a/tests/unit/assets/preload/data/mytype/fizzbuzz.json b/tests/unit/assets/preload/data/mytype/fizzbuzz.json
new file mode 100644
index 000000000..9b160ff55
--- /dev/null
+++ b/tests/unit/assets/preload/data/mytype/fizzbuzz.json
@@ -0,0 +1,15 @@
+{
+  "version": "1.0.0",
+  "id": "fizzbuzz",
+  "name": "nodejs-express-mongoose-demo",
+  "data": [
+    {
+      "foo": "bar",
+      "bar": "foo"
+    },
+    {
+      "foo": "baz",
+      "bar": "baz"
+    }
+  ]
+}
diff --git a/tests/unit/assets/preload/data/mytype/foobar.json b/tests/unit/assets/preload/data/mytype/foobar.json
new file mode 100644
index 000000000..0377a2262
--- /dev/null
+++ b/tests/unit/assets/preload/data/mytype/foobar.json
@@ -0,0 +1,5 @@
+{
+  "version": "0.1.0",
+  "id": 1,
+  "name": "My First App"
+}
diff --git a/tests/unit/assets/preload/data/mytype/junk.json b/tests/unit/assets/preload/data/mytype/junk.json
new file mode 100644
index 000000000..13ae5d1a0
--- /dev/null
+++ b/tests/unit/assets/preload/data/mytype/junk.json
@@ -0,0 +1,4 @@
+{
+  "version": "3.0.0",
+  "info": "stuff"
+}
diff --git a/tests/unit/assets/preload/data/notestyles/funkin.json b/tests/unit/assets/preload/data/notestyles/funkin.json
new file mode 100644
index 000000000..abb039150
--- /dev/null
+++ b/tests/unit/assets/preload/data/notestyles/funkin.json
@@ -0,0 +1,59 @@
+{
+  "version": "1.0.0",
+  "name": "Funkin'",
+  "author": "PhantomArcade",
+  "fallback": null,
+  "assets": {
+    "note": {
+      "assetPath": "shared:arrows",
+      "scale": 1.0,
+      "isPixel": true,
+      "data": {
+        "left": { "prefix": "noteLeft" },
+        "down": { "prefix": "noteDown" },
+        "up": { "prefix": "noteUp" },
+        "right": { "prefix": "noteRight" }
+      }
+    },
+    "noteStrumline": {
+      "assetPath": "shared:arrows",
+      "scale": 1.0,
+      "offsets": [28, 32],
+      "isPixel": true,
+      "data": {
+        "leftStatic": { "prefix": "staticLeft0" },
+        "leftPress": { "prefix": "pressedLeft0" },
+        "leftConfirm": { "prefix": "confirmLeft0" },
+        "leftConfirmHold": { "prefix": "confirmLeft0" },
+        "downStatic": { "prefix": "staticDown0" },
+        "downPress": { "prefix": "pressedDown0" },
+        "downConfirm": { "prefix": "confirmDown0" },
+        "downConfirmHold": { "prefix": "confirmDown0" },
+        "upStatic": { "prefix": "staticUp0" },
+        "upPress": { "prefix": "pressedUp0" },
+        "upConfirm": { "prefix": "confirmUp0" },
+        "upConfirmHold": { "prefix": "confirmUp0" },
+        "rightStatic": { "prefix": "staticRight0" },
+        "rightPress": { "prefix": "pressedRight0" },
+        "rightConfirm": { "prefix": "confirmRight0" },
+        "rightConfirmHold": { "prefix": "confirmRight0" }
+      }
+    },
+    "holdNote": {
+      "assetPath": "NOTE_hold_assets",
+      "data": {}
+    },
+    "noteSplash": {
+      "assetPath": "",
+      "data": {
+        "enabled": true
+      }
+    },
+    "holdNoteCover": {
+      "assetPath": "",
+      "data": {
+        "enabled": true
+      }
+    }
+  }
+}
diff --git a/tests/unit/assets/preload/data/notestyles/test2.json b/tests/unit/assets/preload/data/notestyles/test2.json
new file mode 100644
index 000000000..95a669077
--- /dev/null
+++ b/tests/unit/assets/preload/data/notestyles/test2.json
@@ -0,0 +1,18 @@
+{
+  "version": "1.0.0",
+  "name": "Test2",
+  "author": "Eric",
+  "fallback": "funkin",
+  "assets": {
+    "note": {
+      "assetPath": "shared:coolstuff",
+      "scale": 1.8,
+      "data": {
+        "left": { "prefix": "noteLeft1" },
+        "down": { "prefix": "noteDown3" },
+        "up": { "prefix": "noteUp2" },
+        "right": { "prefix": "noteRight4" }
+      }
+    }
+  }
+}
diff --git a/tests/unit/assets/preload/data/test/blablabla.json b/tests/unit/assets/preload/data/test/blablabla.json
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/assets/preload/data/test/test1.json b/tests/unit/assets/preload/data/test/test1.json
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/assets/preload/data/test/test2.json b/tests/unit/assets/preload/data/test/test2.json
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/assets/shared/images/arrows.png b/tests/unit/assets/shared/images/arrows.png
new file mode 100644
index 000000000..a44368432
Binary files /dev/null and b/tests/unit/assets/shared/images/arrows.png differ
diff --git a/tests/unit/assets/shared/images/arrows.xml b/tests/unit/assets/shared/images/arrows.xml
new file mode 100644
index 000000000..8f3355462
--- /dev/null
+++ b/tests/unit/assets/shared/images/arrows.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextureAtlas imagePath="arrows.png">
+	<SubTexture name="staticLeft0001" x="0" y="0" width="17" height="17"/>
+	<SubTexture name="staticDown0001" x="17" y="0" width="17" height="17"/>
+	<SubTexture name="staticUp0001" x="34" y="0" width="17" height="17"/>
+	<SubTexture name="staticRight0001" x="51" y="0" width="17" height="17"/>
+
+	<SubTexture name="noteLeft0001" x="0" y="17" width="17" height="17"/>
+	<SubTexture name="noteDown0001" x="17" y="17" width="17" height="17"/>
+	<SubTexture name="noteUp0001" x="34" y="17" width="17" height="17"/>
+	<SubTexture name="noteRight0001" x="51" y="17" width="17" height="17"/>
+
+	<SubTexture name="pressedLeft0001" x="0" y="17" width="17" height="17"/>
+	<SubTexture name="pressedDown0001" x="17" y="17" width="17" height="17"/>
+	<SubTexture name="pressedUp0001" x="34" y="17" width="17" height="17"/>
+	<SubTexture name="pressedRight0001" x="51" y="17" width="17" height="17"/>
+
+  <SubTexture name="pressedLeft0002" x="0" y="34" width="17" height="17"/>
+	<SubTexture name="pressedDown0002" x="17" y="34" width="17" height="17"/>
+	<SubTexture name="pressedUp0002" x="34" y="34" width="17" height="17"/>
+	<SubTexture name="pressedRight0002" x="51" y="34" width="17" height="17"/>
+
+	<SubTexture name="confirmLeft0001" x="0" y="51" width="17" height="17"/>
+	<SubTexture name="confirmDown0001" x="17" y="51" width="17" height="17"/>
+	<SubTexture name="confirmUp0001" x="34" y="51" width="17" height="17"/>
+	<SubTexture name="confirmRight0001" x="51" y="51" width="17" height="17"/>
+
+  <SubTexture name="confirmLeft0002" x="0" y="68" width="17" height="17"/>
+	<SubTexture name="confirmDown0002" x="17" y="68" width="17" height="17"/>
+	<SubTexture name="confirmUp0002" x="34" y="68" width="17" height="17"/>
+	<SubTexture name="confirmRight0002" x="51" y="68" width="17" height="17"/>
+</TextureAtlas>
diff --git a/tests/unit/project.xml b/tests/unit/project.xml
new file mode 100644
index 000000000..ccfadce8c
--- /dev/null
+++ b/tests/unit/project.xml
@@ -0,0 +1,91 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project
+	xmlns="http://lime.software/project/1.0.2"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://lime.software/project/1.0.2 http://lime.software/xsd/project-1.0.2.xsd">
+
+	<meta title="FunkinUnitTests" version="1.0.0" />
+	<app file="TestMain" main="TestMain" />
+
+	<!-- Test sources -->
+	<source path="source" />
+
+	<!-- Funkin' sources -->
+	<source path="../../source" />
+
+	<!-- Funkin' dependencies -->
+	<haxelib name="lime" /> <!-- Game engine -->
+	<haxelib name="openfl" /> <!-- Game engine -->
+	<haxelib name="flixel" /> <!-- Game engine -->
+	<haxelib name="flixel-addons" /> <!-- Additional utilities for Flixel -->
+	<haxelib name="hscript" /> <!-- Scripting -->
+	<haxelib name="flixel-ui" /> <!-- UI framework (deprecate this? -->
+	<haxelib name="haxeui-core" /> <!-- UI framework -->
+	<haxelib name="haxeui-flixel" /> <!-- Integrate HaxeUI with Flixel -->
+	<haxelib name="polymod" /> <!-- Modding framework -->
+	<haxelib name="flxanimate" /> <!-- Texture atlas rendering -->
+	<haxelib name="hxCodec" /> <!-- Video playback -->
+	<haxelib name="thx.semver" /> <!-- Semantic version handling -->
+	<haxelib name="json2object" /> <!-- JSON parsing -->
+	<haxelib name="tink_json" /> <!-- JSON parsing -->
+
+	<!-- Test dependencies -->
+	<haxelib name="munit" /> <!-- Unit test execution -->
+	<haxelib name="mcover" /> <!-- Code coverage -->
+	<haxelib name="mockatoo" /> <!-- Mocking -->
+	<haxelib name="hamcrest" /> <!-- Assertions/matching -->
+
+	<!-- This macro allows addition of new functionality to existing Flixel. -->
+	<haxeflag name="--macro" value="addMetadata('@:build(funkin.util.macro.FlxMacro.buildFlxBasic())', 'flixel.FlxBasic')" />
+
+	<!-- Assets -->
+	<assets path="assets/preload" rename="assets" exclude="*.ogg" if="web" />
+	<assets path="assets/preload" rename="assets" exclude="*.mp3" unless="web" />
+	<!--
+	<assets path="assets/songs" library="songs" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/songs" library="songs" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/shared" library="shared" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/shared" library="shared" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/tutorial" library="tutorial" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/tutorial" library="tutorial" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week1" library="week1" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week1" library="week1" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week2" library="week2" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week2" library="week2" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week3" library="week3" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week3" library="week3" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week4" library="week4" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week4" library="week4" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week5" library="week5" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week5" library="week5" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week6" library="week6" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week6" library="week6" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/week7" library="week7" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/week7" library="week7" exclude="*.fla|*.mp3" unless="web" />
+	<assets path="assets/weekend1" library="weekend1" exclude="*.fla|*.ogg" if="web" />
+	<assets path="assets/weekend1" library="weekend1" exclude="*.fla|*.mp3" unless="web" />
+	<library name="songs" preload="true" />
+	<library name="shared" preload="true" />
+	<library name="tutorial" preload="true" />
+	<library name="week1" preload="true" />
+	<library name="week2" preload="true" />
+	<library name="week3" preload="true" />
+	<library name="week4" preload="true" />
+	<library name="week5" preload="true" />
+	<library name="week6" preload="true" />
+	<library name="week7" preload="true" />
+	<library name="weekend1" preload="true" />
+	-->
+
+	<!-- Test defines -->
+	<set name="no-custom-backend" />
+	<set name="unit-test" />
+	<!--<haxedef name="no-inline" />-->
+	<haxedef name="FLX_UNIT_TEST" />
+	<haxedef name="FLX_RECORD" />
+
+	<!-- Manually set up code coverage -->
+	<haxelib name="mcover" />
+	<haxedef name="MCOVER" />
+	<haxeflag name="--macro" value="mcover.MCover.coverage(['funkin'],['../../source', 'source/'],[''])" />
+</project>
diff --git a/tests/unit/source/FunkinAssert.hx b/tests/unit/source/FunkinAssert.hx
new file mode 100644
index 000000000..acfba6723
--- /dev/null
+++ b/tests/unit/source/FunkinAssert.hx
@@ -0,0 +1,77 @@
+package;
+
+import flixel.math.FlxPoint;
+import flixel.math.FlxRect;
+import haxe.PosInfos;
+import massive.munit.Assert;
+
+using flixel.util.FlxArrayUtil;
+
+/**
+ * @see https://github.com/HaxeFlixel/flixel/tree/dev/tests/unit
+ */
+class FunkinAssert
+{
+  /**
+   * Assert if `expected` is within `margin` of `actual`, and fail if not.
+   * Useful for comparting Float values.
+   *
+   * @param expected The expected value of the test.
+   * @param actual The actual value of the test.
+   * @param margin The allowed margin of error between the expected and actual values.
+   * @param info Info on the position this function was called from. Magic value, passed automatically.
+   */
+  public static function areNear(expected:Float, actual:Float, margin:Float = 0.001, ?info:PosInfos):Void
+  {
+    if (areNearHelper(expected, actual)) Assert.assertionCount++;
+    else
+      Assert.fail('Value [$actual] is not within [$margin] of [$expected]', info);
+  }
+
+  public static function rectsNear(expected:FlxRect, actual:FlxRect, margin:Float = 0.001, ?info:PosInfos):Void
+  {
+    var areNear = areNearHelper(expected.x, actual.x, margin)
+      && areNearHelper(expected.y, actual.y, margin)
+      && areNearHelper(expected.width, actual.width, margin)
+      && areNearHelper(expected.height, actual.height, margin);
+
+    if (areNear) Assert.assertionCount++;
+    else
+      Assert.fail('Value [$actual] is not within [$margin] of [$expected]', info);
+  }
+
+  static function areNearHelper(expected:Float, actual:Float, margin:Float = 0.001):Bool
+  {
+    return actual >= expected - margin && actual <= expected + margin;
+  }
+
+  public static function arraysEqual<T>(expected:Array<T>, actual:Array<T>, ?info:PosInfos):Void
+  {
+    if (expected.equals(actual)) Assert.assertionCount++;
+    else
+      Assert.fail('\nExpected\n   ${expected}\nbut was\n   ${actual}\n', info);
+  }
+
+  public static function arraysNotEqual<T>(expected:Array<T>, actual:Array<T>, ?info:PosInfos):Void
+  {
+    if (!expected.equals(actual)) Assert.assertionCount++;
+    else
+      Assert.fail('\nValue\n   ${actual}\nwas equal to\n   ${expected}\n', info);
+  }
+
+  public static function pointsEqual(expected:FlxPoint, actual:FlxPoint, ?msg:String, ?info:PosInfos)
+  {
+    if (expected.equals(actual)) Assert.assertionCount++;
+    else if (msg != null) Assert.fail(msg, info);
+    else
+      Assert.fail("Value [" + actual + "] was not equal to expected value [" + expected + "]", info);
+  }
+
+  public static function pointsNotEqual(expected:FlxPoint, actual:FlxPoint, ?msg:String, ?info:PosInfos)
+  {
+    if (!expected.equals(actual)) Assert.assertionCount++;
+    else if (msg != null) Assert.fail(msg, info);
+    else
+      Assert.fail("Value [" + actual + "] was equal to value [" + expected + "]", info);
+  }
+}
diff --git a/tests/unit/source/FunkinTest.hx b/tests/unit/source/FunkinTest.hx
new file mode 100644
index 000000000..7e0e0b26c
--- /dev/null
+++ b/tests/unit/source/FunkinTest.hx
@@ -0,0 +1,105 @@
+package;
+
+import openfl.utils.Assets;
+import openfl.errors.Error;
+import flixel.FlxG;
+import flixel.FlxState;
+import flixel.tweens.FlxTween;
+import flixel.util.FlxDestroyUtil.IFlxDestroyable;
+import massive.munit.Assert;
+
+/**
+ * @see https://github.com/HaxeFlixel/flixel/tree/dev/tests/unit
+ */
+class FunkinTest
+{
+  public static final MS_PER_STEP:Float = 1.0 / 60.0 * 1000;
+
+  // approx. amount of ticks at 60 fps
+  static inline var TICKS_PER_FRAME:UInt = 25;
+  static var totalSteps:UInt = 0;
+
+  var destroyable:IFlxDestroyable;
+
+  public function new() {}
+
+  @After
+  @:access(flixel)
+  function after()
+  {
+    // Redefine how the game gets the time during tests.
+    FlxG.game.getTimer = function() {
+      return totalSteps * TICKS_PER_FRAME;
+    }
+
+    // make sure we have the same starting conditions for each test
+    resetGame();
+  }
+
+  /**
+   * Advance the game simulation.
+   * @param steps The amount to advance the game by.
+   * @param callback A function to call after each step.
+   */
+  @:access(flixel)
+  function step(steps:UInt = 1, ?callback:Void->Void)
+  {
+    for (i in 0...steps)
+    {
+      FlxG.game.step();
+      if (callback != null) callback();
+      totalSteps++;
+    }
+  }
+
+  function resetGame()
+  {
+    FlxG.resetGame();
+    step();
+  }
+
+  function switchState(nextState:FlxState)
+  {
+    FlxG.switchState(nextState);
+    step();
+  }
+
+  function resetState()
+  {
+    FlxG.resetState();
+    step();
+  }
+
+  @Test
+  public function testAssert()
+  {
+    Assert.areEqual(4, 2 + 2);
+  }
+
+  @Test
+  function testDestroy()
+  {
+    if (destroyable == null)
+    {
+      return;
+    }
+
+    try
+    {
+      destroyable.destroy();
+      destroyable.destroy();
+    }
+    catch (e:Error)
+    {
+      Assert.fail(e.message);
+    }
+  }
+
+  function finishTween(tween:FlxTween)
+  {
+    while (!tween.finished)
+    {
+      step();
+    }
+  }
+}
diff --git a/tests/unit/source/MockTest.hx b/tests/unit/source/MockTest.hx
new file mode 100644
index 000000000..c1ae0a90d
--- /dev/null
+++ b/tests/unit/source/MockTest.hx
@@ -0,0 +1,60 @@
+package;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.DateUtil;
+
+class MockTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testMock()
+  {
+    // Test that mocking works.
+
+    var mockSprite = mockatoo.Mockatoo.mock(flixel.FlxSprite);
+    var mockAnim = mockatoo.Mockatoo.mock(flixel.animation.FlxAnimationController);
+    mockSprite.animation = mockAnim;
+
+    var animData:funkin.data.animation.AnimationData =
+      {
+        name: "testAnim",
+        prefix: "blablabla"
+      };
+
+    mockSprite.animation.addByPrefix("testAnim", "blablabla", 24, false, false, false);
+
+    // Verify that the method was called once.
+    // If not, a VerificationException will be thrown and the test will fail.
+    mockatoo.Mockatoo.verify(mockAnim.addByPrefix("testAnim", "blablabla", 24, false, false, false), times(1));
+
+    try
+    {
+      // Attempt to verify the method was called.
+      // This should FAIL, since we didn't call the method.
+      mockatoo.Mockatoo.verify(mockAnim.addByIndices("testAnim", "blablabla", [], "", 24, false, false, false), times(1));
+      Assert.fail("Mocking function should have thrown but didn't.");
+    }
+    catch (_:mockatoo.exception.VerificationException)
+    {
+      // Expected.
+    }
+  }
+}
diff --git a/tests/unit/source/TestMain.hx b/tests/unit/source/TestMain.hx
new file mode 100644
index 000000000..a3fbdb428
--- /dev/null
+++ b/tests/unit/source/TestMain.hx
@@ -0,0 +1,77 @@
+package;
+
+import openfl.Lib;
+import flixel.FlxGame;
+import flixel.FlxState;
+import massive.munit.TestRunner;
+import massive.munit.client.HTTPClient;
+import massive.munit.client.SummaryReportClient;
+
+/**
+ * Auto generated Test Application.
+ * Refer to munit command line tool for more information (haxelib run munit)
+ */
+class TestMain
+{
+  /**
+   * If true, include a report with each ignored test and their descriptions.
+   */
+  static final INCLUDE_IGNORED_REPORT:Bool = false;
+
+  static function main()
+  {
+    new TestMain();
+  }
+
+  public function new()
+  {
+    // Flixel was not designed for unit testing so we can only have one instance for now.
+    Lib.current.stage.addChild(new FlxGame(640, 480, FlxState, 60, 60, true));
+
+    var suites = new Array<Class<massive.munit.TestSuite>>();
+    suites.push(TestSuite);
+
+    #if MCOVER
+    // Print individual test results alongside coverage results for each test class,
+    // as well as a final coverage report for the entire test suite.
+    var innerClient = new massive.munit.client.RichPrintClient(INCLUDE_IGNORED_REPORT);
+    var client = new mcover.coverage.munit.client.MCoverPrintClient(innerClient);
+    // Print final test results alongside detailed coverage results for the test suite.
+    var httpClient = new HTTPClient(new mcover.coverage.munit.client.MCoverSummaryReportClient());
+    // NOTE: You can also create a custom ICoverageTestResultClient implementation
+
+    mcover.coverage.MCoverage.getLogger().addClient(new mcover.coverage.client.CodecovJsonPrintClient());
+    #else
+    // Print individual test results.
+    var client = new massive.munit.client.RichPrintClient(INCLUDE_IGNORED_REPORT);
+    // Print final test suite results.
+    var httpClient = new HTTPClient(new SummaryReportClient());
+    #end
+
+    var runner = new TestRunner(client);
+    runner.addResultClient(httpClient);
+
+    runner.completionHandler = completionHandler;
+    runner.run(suites);
+  }
+
+  /**
+   * updates the background color and closes the current browser
+   * for flash and html targets (useful for continuos integration servers)
+   */
+  function completionHandler(successful:Bool):Void
+  {
+    try
+    {
+      #if flash
+      openfl.external.ExternalInterface.call("testResult", successful);
+      #elseif js
+      js.Lib.eval("testResult(" + successful + ");");
+      #elseif sys
+      Sys.exit(successful ? 0 : 1);
+      #end
+    }
+    // if run from outside browser can get error which we can ignore
+    catch (e:Dynamic) {}
+  }
+}
diff --git a/tests/unit/source/_template.hxtemplate b/tests/unit/source/_template.hxtemplate
new file mode 100644
index 000000000..47a546bd0
--- /dev/null
+++ b/tests/unit/source/_template.hxtemplate
@@ -0,0 +1,30 @@
+package funkin.play;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.play.PlayState;
+
+@:access(funkin.play.PlayState)
+class Template extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function test() {}
+}
diff --git a/tests/unit/source/flixel/FlxGTest.hx b/tests/unit/source/flixel/FlxGTest.hx
new file mode 100644
index 000000000..5f201a9f0
--- /dev/null
+++ b/tests/unit/source/flixel/FlxGTest.hx
@@ -0,0 +1,107 @@
+package flixel;
+
+import massive.munit.Assert;
+
+@:access(flixel.FlxG)
+class FlxGTest extends FunkinTest
+{
+  @Test function testVERSIONNull():Void
+    Assert.isNotNull(FlxG.VERSION);
+
+  @Test function testGameNull():Void
+    Assert.isNotNull(FlxG.game);
+
+  @Test function testStageNull():Void
+    Assert.isNotNull(FlxG.stage);
+
+  @Test function testStateNull():Void
+    Assert.isNotNull(FlxG.state);
+
+  @Test function testWorldBoundsNull():Void
+    Assert.isNotNull(FlxG.worldBounds);
+
+  @Test function testSaveNull():Void
+    Assert.isNotNull(FlxG.save);
+
+  #if FLX_MOUSE
+  @Test function testMouseNull():Void
+    Assert.isNotNull(FlxG.mouse);
+  #end
+
+  #if FLX_TOUCH
+  @Test function testTouchNull():Void
+    Assert.isNotNull(FlxG.touches);
+  #end
+
+  #if FLX_POINTER_INPUT
+  @Test function testSwipesNull():Void
+    Assert.isNotNull(FlxG.swipes);
+  #end
+
+  #if FLX_KEYBOARD
+  @Test function testKeysNull():Void
+    Assert.isNotNull(FlxG.keys);
+  #end
+
+  #if FLX_GAMEPAD
+  @Test function testGamepadsNull():Void
+    Assert.isNotNull(FlxG.gamepads);
+  #end
+
+  #if android
+  @Test function testAndroidNull():Void
+    Assert.isNotNull(FlxG.android);
+  #end
+
+  #if js
+  @Test function testHtml5Null():Void
+    Assert.isNotNull(FlxG.html5);
+  #end
+
+  @Test function testInputsNull():Void
+    Assert.isNotNull(FlxG.inputs);
+
+  @Test function testConsoleNull():Void
+    Assert.isNotNull(FlxG.console);
+
+  @Test function testLogNull():Void
+    Assert.isNotNull(FlxG.log);
+
+  @Test function testWatchNull():Void
+    Assert.isNotNull(FlxG.watch);
+
+  @Test function testDebuggerNull():Void
+    Assert.isNotNull(FlxG.debugger);
+
+  @Test function testVcrNull():Void
+    Assert.isNotNull(FlxG.vcr);
+
+  @Test function testBitmapNull():Void
+    Assert.isNotNull(FlxG.bitmap);
+
+  @Test function testCamerasNull():Void
+    Assert.isNotNull(FlxG.cameras);
+
+  @Test function testPluginsNull():Void
+    Assert.isNotNull(FlxG.plugins);
+
+  #if FLX_SOUND_SYSTEM
+  @Test function testSoundNull():Void
+    Assert.isNotNull(FlxG.sound);
+  #end
+
+  @Test function testScaleModeNull():Void
+    Assert.isNotNull(FlxG.scaleMode);
+
+  @Test
+  function testDefaultWidth():Void
+  {
+    Assert.areEqual(640, FlxG.width);
+  }
+
+  @Test
+  function testDefaultHeight():Void
+  {
+    Assert.areEqual(480, FlxG.height);
+  }
+}
diff --git a/tests/unit/source/funkin/ConductorTest.hx b/tests/unit/source/funkin/ConductorTest.hx
new file mode 100644
index 000000000..856c52186
--- /dev/null
+++ b/tests/unit/source/funkin/ConductorTest.hx
@@ -0,0 +1,550 @@
+package funkin;
+
+import flixel.FlxG;
+import flixel.FlxState;
+import funkin.Conductor;
+import funkin.play.song.SongData.SongTimeChange;
+import funkin.util.Constants;
+import massive.munit.Assert;
+
+@:access(funkin.Conductor)
+class ConductorTest extends FunkinTest
+{
+  var conductorState:ConductorState;
+
+  @Before
+  function before()
+  {
+    resetGame();
+
+    // The ConductorState will advance the conductor when step() is called.
+    FlxG.switchState(conductorState = new ConductorState());
+
+    Conductor.reset();
+  }
+
+  @Test
+  function testDefaultValues():Void
+  {
+    // NOTE: Expected value comes first.
+
+    Assert.areEqual([], Conductor.timeChanges);
+    Assert.areEqual(null, Conductor.currentTimeChange);
+
+    Assert.areEqual(0, Conductor.songPosition);
+    Assert.areEqual(Constants.DEFAULT_BPM, Conductor.bpm);
+    Assert.areEqual(null, Conductor.bpmOverride);
+
+    Assert.areEqual(600, Conductor.beatLengthMs);
+
+    Assert.areEqual(4, Conductor.timeSignatureNumerator);
+    Assert.areEqual(4, Conductor.timeSignatureDenominator);
+
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    Assert.areEqual(0.0, Conductor.currentStepTime);
+
+    Assert.areEqual(150, Conductor.stepLengthMs);
+  }
+
+  /**
+   * Tests implementation of `update()`, and how it affects
+   * `currentBeat`, `currentStep`, `currentStepTime`, and the `beatHit` and `stepHit` signals.
+   */
+  @Test
+  function testUpdate():Void
+  {
+    Assert.areEqual(0, Conductor.songPosition);
+
+    step(); // 1
+
+    var BPM_100_STEP_TIME = 1 / 9;
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 1, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(1 / 9, Conductor.currentStepTime);
+
+    step(7); // 8
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 8, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(8 / 9, Conductor.currentStepTime);
+
+    Assert.areEqual(0, conductorState.beatsHit);
+    Assert.areEqual(0, conductorState.stepsHit);
+
+    step(); // 9
+
+    Assert.areEqual(0, conductorState.beatsHit);
+    Assert.areEqual(1, conductorState.stepsHit);
+    conductorState.beatsHit = 0;
+    conductorState.stepsHit = 0;
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 9, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(1, Conductor.currentStep);
+    FunkinAssert.areNear(1.0, Conductor.currentStepTime);
+
+    step(35 - 9); // 35
+
+    Assert.areEqual(0, conductorState.beatsHit);
+    Assert.areEqual(2, conductorState.stepsHit);
+    conductorState.beatsHit = 0;
+    conductorState.stepsHit = 0;
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 35, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(3, Conductor.currentStep);
+    FunkinAssert.areNear(3.0 + 8 / 9, Conductor.currentStepTime);
+
+    step(); // 36
+
+    Assert.areEqual(1, conductorState.beatsHit);
+    Assert.areEqual(1, conductorState.stepsHit);
+    conductorState.beatsHit = 0;
+    conductorState.stepsHit = 0;
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 36, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(4, Conductor.currentStep);
+    FunkinAssert.areNear(4.0, Conductor.currentStepTime);
+
+    step(50 - 36); // 50
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 50, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(5, Conductor.currentStep);
+    FunkinAssert.areNear(5.555555, Conductor.currentStepTime);
+
+    step(49); // 99
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 99, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(11, Conductor.currentStep);
+    FunkinAssert.areNear(11.0, Conductor.currentStepTime);
+
+    step(1); // 100
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 100, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(11, Conductor.currentStep);
+    FunkinAssert.areNear(11.111111, Conductor.currentStepTime);
+  }
+
+  @Test
+  function testUpdateForcedBPM():Void
+  {
+    Conductor.forceBPM(60);
+
+    Assert.areEqual(0, Conductor.songPosition);
+
+    // 60 beats per minute = 1 beat per second
+    // 1 beat per second = 1/60 beats per frame = 4/60 steps per frame
+    step(); // Advances time 1/60 of 1 second.
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 1, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(4 / 60, Conductor.currentStepTime); // 1/60 of 1 beat = 4/60 of 1 step
+
+    step(14 - 1); // 14
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 14, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(1.0 - 4 / 60, Conductor.currentStepTime); // 1/60 of 1 beat = 4/60 of 1 step
+
+    step(); // 15
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 15, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(1, Conductor.currentStep);
+    FunkinAssert.areNear(1.0, Conductor.currentStepTime); // 1/60 of 1 beat = 4/60 of 1 step
+
+    step(45 - 1); // 59
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 59, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(3, Conductor.currentStep);
+    FunkinAssert.areNear(4.0 - 4 / 60, Conductor.currentStepTime);
+
+    step(); // 60
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 60, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(4, Conductor.currentStep);
+    FunkinAssert.areNear(4.0, Conductor.currentStepTime);
+
+    step(); // 61
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 61, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(4, Conductor.currentStep);
+    FunkinAssert.areNear(4.0 + 4 / 60, Conductor.currentStepTime);
+  }
+
+  @Test
+  function testSingleTimeChange():Void
+  {
+    // Start the song with a BPM of 120.
+    var songTimeChanges:Array<SongTimeChange> = [
+      {
+        t: 0,
+        b: 0,
+        bpm: 120,
+        n: 4,
+        d: 4,
+        bt: [4, 4, 4, 4]
+      }, // 120 bpm starting 0 sec/0 beats
+    ];
+    Conductor.mapTimeChanges(songTimeChanges);
+
+    // All should be at 0.
+    FunkinAssert.areNear(0, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(0.0, Conductor.currentStepTime); // 2/120 of 1 beat = 8/120 of 1 step
+
+    // 120 beats per minute = 2 beat per second
+    // 2 beat per second = 2/60 beats per frame = 16/120 steps per frame
+    step(); // Advances time 1/60 of 1 second.
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 1, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(16 / 120, Conductor.currentStepTime); // 2/120 of 1 beat = 8/120 of 1 step
+
+    step(15 - 1); // 15
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 15, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(2, Conductor.currentStep);
+    FunkinAssert.areNear(2.0, Conductor.currentStepTime); // 2/60 of 1 beat = 8/60 of 1 step
+
+    step(45 - 1); // 59
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 59, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(7, Conductor.currentStep);
+    FunkinAssert.areNear(7.0 + 104 / 120, Conductor.currentStepTime);
+
+    step(); // 60
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 60, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(8, Conductor.currentStep);
+    FunkinAssert.areNear(8.0, Conductor.currentStepTime);
+
+    step(); // 61
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 61, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(8, Conductor.currentStep);
+    FunkinAssert.areNear(8.0 + 8 / 60, Conductor.currentStepTime);
+  }
+
+  @Test
+  function testDoubleTimeChange():Void
+  {
+    // Start the song with a BPM of 120.
+    var songTimeChanges:Array<SongTimeChange> = [
+      {
+        t: 0,
+        b: 0,
+        bpm: 120,
+        n: 4,
+        d: 4,
+        bt: [4, 4, 4, 4]
+      }, // 120 bpm starting 0 sec/0 beats
+      {
+        t: 3000,
+        b: 6,
+        bpm: 90,
+        n: 4,
+        d: 4,
+        bt: [4, 4, 4, 4]
+      } // 90 bpm starting 3 sec/6 beats
+    ];
+    Conductor.mapTimeChanges(songTimeChanges);
+
+    // All should be at 0.
+    FunkinAssert.areNear(0, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(0.0, Conductor.currentStepTime); // 2/120 of 1 beat = 8/120 of 1 step
+
+    // 120 beats per minute = 2 beat per second
+    // 2 beat per second = 2/60 beats per frame = 16/120 steps per frame
+    step(); // Advances time 1/60 of 1 second.
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 1, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(16 / 120, Conductor.currentStepTime); // 4/120 of 1 beat = 16/120 of 1 step
+
+    step(60 - 1 - 1); // 59
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 59, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(7, Conductor.currentStep);
+    FunkinAssert.areNear(7.0 + 104 / 120, Conductor.currentStepTime);
+
+    step(); // 60
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 60, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(8, Conductor.currentStep);
+    FunkinAssert.areNear(8.0, Conductor.currentStepTime);
+
+    step(); // 61
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 61, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(8, Conductor.currentStep);
+    FunkinAssert.areNear(8.0 + 8 / 60, Conductor.currentStepTime);
+
+    step(179 - 61); // 179
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 179, Conductor.songPosition);
+    Assert.areEqual(5, Conductor.currentBeat);
+    Assert.areEqual(23, Conductor.currentStep);
+    FunkinAssert.areNear(23.0 + 52 / 60, Conductor.currentStepTime);
+
+    step(); // 180 (3 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 180, Conductor.songPosition);
+    Assert.areEqual(6, Conductor.currentBeat);
+    Assert.areEqual(24, Conductor.currentStep);
+    FunkinAssert.areNear(24.0, Conductor.currentStepTime);
+
+    step(); // 181 (3 + 1/60 seconds)
+    // BPM has switched to 90!
+    // 90 beats per minute = 1.5 beat per second
+    // 1.5 beat per second = 1.5/60 beats per frame = 3/120 beats per frame
+    // = 12/120 steps per frame
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 181, Conductor.songPosition);
+    Assert.areEqual(6, Conductor.currentBeat);
+    Assert.areEqual(24, Conductor.currentStep);
+    FunkinAssert.areNear(24.0 + 12 / 120, Conductor.currentStepTime);
+
+    step(59); // 240 (4 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 240, Conductor.songPosition);
+    Assert.areEqual(7, Conductor.currentBeat);
+    Assert.areEqual(30, Conductor.currentStep);
+    FunkinAssert.areNear(30.0, Conductor.currentStepTime);
+
+    step(); // 241 (4 + 1/60 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 241, Conductor.songPosition);
+    Assert.areEqual(7, Conductor.currentBeat);
+    Assert.areEqual(30, Conductor.currentStep);
+    FunkinAssert.areNear(30.0 + 12 / 120, Conductor.currentStepTime);
+  }
+
+  @Test
+  function testTripleTimeChange():Void
+  {
+    // Start the song with a BPM of 120, then move to 90, then move to 180.
+    var songTimeChanges:Array<SongTimeChange> = [
+      {
+        t: 0,
+        b: null,
+        bpm: 120,
+        n: 4,
+        d: 4,
+        bt: [4, 4, 4, 4]
+      }, // 120 bpm starting 0 sec/0 beats
+      {
+        t: 3000,
+        b: null,
+        bpm: 90,
+        n: 4,
+        d: 4,
+        bt: [4, 4, 4, 4]
+      }, // 90 bpm starting 3 sec/6 beats
+      {
+        t: 6000,
+        b: null,
+        bpm: 180,
+        n: 4,
+        d: 4,
+        bt: [4, 4, 4, 4]
+      } // 90 bpm starting 3 sec/6 beats
+    ];
+    Conductor.mapTimeChanges(songTimeChanges);
+
+    // Verify time changes.
+    Assert.areEqual(3, Conductor.timeChanges.length);
+    FunkinAssert.areNear(0, Conductor.timeChanges[0].beatTime);
+    FunkinAssert.areNear(6, Conductor.timeChanges[1].beatTime);
+    FunkinAssert.areNear(10.5, Conductor.timeChanges[2].beatTime);
+
+    // All should be at 0.
+    FunkinAssert.areNear(0, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(0.0, Conductor.currentStepTime); // 2/120 of 1 beat = 8/120 of 1 step
+
+    // 120 beats per minute = 2 beat per second
+    // 2 beat per second = 2/60 beats per frame = 16/120 steps per frame
+    step(); // Advances time 1/60 of 1 second.
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 1, Conductor.songPosition);
+    Assert.areEqual(0, Conductor.currentBeat);
+    Assert.areEqual(0, Conductor.currentStep);
+    FunkinAssert.areNear(16 / 120, Conductor.currentStepTime); // 4/120 of 1 beat = 16/120 of 1 step
+
+    step(60 - 1 - 1); // 59
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 59, Conductor.songPosition);
+    Assert.areEqual(1, Conductor.currentBeat);
+    Assert.areEqual(7, Conductor.currentStep);
+    FunkinAssert.areNear(7 + 104 / 120, Conductor.currentStepTime);
+
+    step(); // 60
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 60, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(8, Conductor.currentStep);
+    FunkinAssert.areNear(8.0, Conductor.currentStepTime);
+
+    step(); // 61
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 61, Conductor.songPosition);
+    Assert.areEqual(2, Conductor.currentBeat);
+    Assert.areEqual(8, Conductor.currentStep);
+    FunkinAssert.areNear(8.0 + 8 / 60, Conductor.currentStepTime);
+
+    step(179 - 61); // 179
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 179, Conductor.songPosition);
+    Assert.areEqual(5, Conductor.currentBeat);
+    Assert.areEqual(23, Conductor.currentStep);
+    FunkinAssert.areNear(23.0 + 52 / 60, Conductor.currentStepTime);
+
+    step(); // 180 (3 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 180, Conductor.songPosition);
+    Assert.areEqual(6, Conductor.currentBeat);
+    Assert.areEqual(24, Conductor.currentStep); // 23.999 => 24
+    FunkinAssert.areNear(24.0, Conductor.currentStepTime);
+
+    step(); // 181 (3 + 1/60 seconds)
+    // BPM has switched to 90!
+    // 90 beats per minute = 1.5 beat per second
+    // 1.5 beat per second = 1.5/60 beats per frame = 3/120 beats per frame
+    // = 12/120 steps per frame
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 181, Conductor.songPosition);
+    Assert.areEqual(6, Conductor.currentBeat);
+    Assert.areEqual(24, Conductor.currentStep);
+    FunkinAssert.areNear(24.0 + 12 / 120, Conductor.currentStepTime);
+
+    step(60 - 1 - 1); // 240 (4 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 239, Conductor.songPosition);
+    Assert.areEqual(7, Conductor.currentBeat);
+    Assert.areEqual(29, Conductor.currentStep);
+    FunkinAssert.areNear(29.0 + 108 / 120, Conductor.currentStepTime);
+
+    step(); // 240 (4 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 240, Conductor.songPosition);
+    Assert.areEqual(7, Conductor.currentBeat);
+    Assert.areEqual(30, Conductor.currentStep);
+    FunkinAssert.areNear(30.0, Conductor.currentStepTime);
+
+    step(); // 241 (4 + 1/60 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 241, Conductor.songPosition);
+    Assert.areEqual(7, Conductor.currentBeat);
+    Assert.areEqual(30, Conductor.currentStep);
+    FunkinAssert.areNear(30.0 + 12 / 120, Conductor.currentStepTime);
+
+    step(359 - 241); // 359 (5 + 59/60 seconds)
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 359, Conductor.songPosition);
+    Assert.areEqual(10, Conductor.currentBeat);
+    Assert.areEqual(41, Conductor.currentStep);
+    FunkinAssert.areNear(41 + 108 / 120, Conductor.currentStepTime);
+
+    step(); // 360
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 360, Conductor.songPosition);
+    Assert.areEqual(10, Conductor.currentBeat);
+    Assert.areEqual(42, Conductor.currentStep); // 41.999
+    FunkinAssert.areNear(42.0, Conductor.currentStepTime);
+
+    step(); // 361
+    // BPM has switched to 180!
+    // 180 beats per minute = 3 beat per second
+    // 3 beat per second = 3/60 beats per frame
+    // = 12/60 steps per frame
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 361, Conductor.songPosition);
+    Assert.areEqual(10, Conductor.currentBeat);
+    Assert.areEqual(42, Conductor.currentStep);
+    FunkinAssert.areNear(42.0 + 12 / 60, Conductor.currentStepTime);
+
+    step(); // 362
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 362, Conductor.songPosition);
+    Assert.areEqual(10, Conductor.currentBeat);
+    Assert.areEqual(42, Conductor.currentStep);
+    FunkinAssert.areNear(42.0 + 24 / 60, Conductor.currentStepTime);
+
+    step(3); // 365
+
+    FunkinAssert.areNear(FunkinTest.MS_PER_STEP * 365, Conductor.songPosition);
+    Assert.areEqual(10, Conductor.currentBeat);
+    Assert.areEqual(43, Conductor.currentStep); // 42.999 => 42
+    FunkinAssert.areNear(43.0, Conductor.currentStepTime);
+  }
+}
+
+class ConductorState extends FlxState
+{
+  public var beatsHit:Int = 0;
+  public var stepsHit:Int = 0;
+
+  public function new()
+  {
+    super();
+  }
+
+  function beatHit():Void
+  {
+    beatsHit += 1;
+  }
+
+  function stepHit():Void
+  {
+    stepsHit += 1;
+  }
+
+  public override function create():Void
+  {
+    super.create();
+    Conductor.beatHit.add(this.beatHit);
+    Conductor.stepHit.add(this.stepHit);
+  }
+
+  public override function destroy():Void
+  {
+    super.destroy();
+    Conductor.beatHit.remove(this.beatHit);
+    Conductor.stepHit.remove(this.stepHit);
+  }
+
+  public override function update(elapsed:Float)
+  {
+    super.update(elapsed);
+
+    // On each step, increment the Conductor as though the song was playing.
+    Conductor.update(Conductor.songPosition + elapsed * Constants.MS_PER_SEC);
+  }
+}
diff --git a/tests/unit/source/funkin/data/BaseRegistryTest.hx b/tests/unit/source/funkin/data/BaseRegistryTest.hx
new file mode 100644
index 000000000..3532c4403
--- /dev/null
+++ b/tests/unit/source/funkin/data/BaseRegistryTest.hx
@@ -0,0 +1,228 @@
+package funkin.data;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.data.BaseRegistry;
+import funkin.util.SortUtil;
+import funkin.util.VersionUtil;
+
+@:access(funkin.data.BaseRegistry)
+class BaseRegistryTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testMyTypeRegistry()
+  {
+    // This shouldn't crash.
+    MyTypeRegistry.instance.loadEntries();
+
+    // Ensure all entries were loaded.
+    var entryList = MyTypeRegistry.instance.listEntryIds();
+    entryList.sort(SortUtil.alphabetically);
+
+    Assert.areEqual(entryList, [
+      "blablabla",
+      "fizzbuzz",
+      "foobar",
+      // "junk"
+    ]);
+
+    // Ensure this one is not in the list.
+    Assert.areEqual(entryList.indexOf("junk"), -1);
+
+    // Ensure blablabla got parsed correctly.
+    var blablabla = MyTypeRegistry.instance.fetchEntry("blablabla");
+    Assert.areEqual(blablabla.id, "blablabla");
+    Assert.areEqual(blablabla._data.version, "1.0.0");
+    Assert.areEqual(blablabla._data.name, "blablabla API");
+  }
+}
+
+typedef MyTypeData =
+{
+  /**
+   * The version number of the data schema.
+   * When making changes to the note style data format, this should be incremented,
+   * and a migration function should be added to handle old versions.
+   */
+  @:default(funkin.data.BaseRegistryTest.MyTypeRegistry.DATA_VERSION)
+  var version:String;
+
+  var id:String;
+  var name:String;
+  var data:Array<MySubTypeData>;
+}
+
+typedef MySubTypeData =
+{
+  var foo:String;
+  var bar:String;
+};
+
+typedef MyTypeData_v0_1_x =
+{
+  var version:String;
+  var id:Int;
+  var name:String;
+};
+
+class MyType implements IRegistryEntry<MyTypeData>
+{
+  /**
+   * The ID of the mytype.
+   */
+  public final id:String;
+
+  /**
+   * Mytype data as parsed from the JSON file.
+   */
+  public final _data:MyTypeData;
+
+  /**
+   * @param id The ID of the JSON file to parse.
+   */
+  public function new(id:String)
+  {
+    this.id = id;
+    _data = _fetchData(id);
+
+    if (_data == null)
+    {
+      throw 'Could not parse mytype data for id: $id';
+    }
+  }
+
+  public function destroy():Void {}
+
+  public function toString():String
+  {
+    return 'MyType($id)';
+  }
+
+  public function _fetchData(id:String):Null<MyTypeData>
+  {
+    return MyTypeRegistry.instance.parseEntryDataWithMigration(id, MyTypeRegistry.instance.fetchEntryVersion(id));
+  }
+
+  public function getSubData():Array<MySubTypeData>
+  {
+    return _data.data;
+  }
+}
+
+class MyTypeRegistry extends BaseRegistry<MyType, MyTypeData>
+{
+  /**
+   * The current version string for the note style data format.
+   * Handle breaking changes by incrementing this value
+   * and adding migration to the `migrateMyTypeData()` function.
+   */
+  public static final DATA_VERSION:String = "1.0.0";
+
+  public static final instance:MyTypeRegistry = new MyTypeRegistry();
+
+  public function new()
+  {
+    super('MYTYPE', 'mytype');
+  }
+
+  /**
+   * Read, parse, and validate the JSON data and produce the corresponding data object.
+   */
+  public function parseEntryData(id:String):Null<MyTypeData>
+  {
+    // JsonParser does not take type parameters,
+    // otherwise this function would be in BaseRegistry.
+    var parser = new json2object.JsonParser<MyTypeData>();
+    var jsonStr:String = loadEntryFile(id);
+
+    parser.fromJson(jsonStr);
+
+    if (parser.errors.length > 0)
+    {
+      trace('[${registryId}] Failed to parse entry data: ${id}');
+      for (error in parser.errors)
+      {
+        trace(error);
+      }
+      return null;
+    }
+    return parser.value;
+  }
+
+  /**
+   * Read, parse, and validate the JSON data and produce the corresponding data object.
+   */
+  public function parseEntryData_v0_1_x(id:String):Null<MyTypeData>
+  {
+    // JsonParser does not take type parameters,
+    // otherwise this function would be in BaseRegistry.
+    var parser = new json2object.JsonParser<MyTypeData_v0_1_x>();
+    var jsonStr:String = loadEntryFile(id);
+
+    parser.fromJson(jsonStr);
+
+    if (parser.errors.length > 0)
+    {
+      trace('[${registryId}] Failed to parse entry data: ${id}');
+      for (error in parser.errors)
+      {
+        trace(error);
+      }
+      return null;
+    }
+
+    var oldData:MyTypeData_v0_1_x = parser.value;
+
+    var result:MyTypeData =
+      {
+        version: DATA_VERSION,
+        id: '${oldData.id}',
+        name: oldData.name,
+        data: []
+      };
+
+    return result;
+  }
+
+  public override function parseEntryDataWithMigration(id:String, version:thx.semver.Version):Null<MyTypeData>
+  {
+    if (VersionUtil.validateVersion(version, "0.1.x"))
+    {
+      trace('Migrating mytype data from ${version} to ${DATA_VERSION}');
+      return parseEntryData_v0_1_x(id);
+    }
+    else
+    {
+      trace('Parsing mytype data with version ${version}');
+      return super.parseEntryDataWithMigration(id, version);
+    }
+  }
+
+  function createScriptedEntry(clsName:String):MyType
+  {
+    return null;
+  }
+
+  function getScriptedClassNames():Array<String>
+  {
+    return [];
+  }
+}
diff --git a/tests/unit/source/funkin/data/notestyle/NoteStyleRegistryTest.hx b/tests/unit/source/funkin/data/notestyle/NoteStyleRegistryTest.hx
new file mode 100644
index 000000000..ec33b37d7
--- /dev/null
+++ b/tests/unit/source/funkin/data/notestyle/NoteStyleRegistryTest.hx
@@ -0,0 +1,90 @@
+package funkin.data.notestyle;
+
+import funkin.data.notestyle.NoteStyleRegistry;
+import funkin.play.notes.notestyle.NoteStyle;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import massive.munit.util.Timer;
+
+@:access(funkin.play.notes.notestyle.NoteStyle)
+@:access(funkin.data.notestyle.NoteStyleRegistry)
+class NoteStyleRegistryTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass()
+  {
+    NoteStyleRegistry.instance.loadEntries();
+  }
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testValid()
+  {
+    Assert.isNotNull(NoteStyleRegistry.instance);
+  }
+
+  @Test
+  public function testParseEntryData()
+  {
+    var result:NoteStyleData = NoteStyleRegistry.instance.parseEntryData("test2");
+
+    Assert.areEqual(result.version, "1.0.0");
+    Assert.areEqual(result.name, "Test2");
+    Assert.areEqual(result.author, "Eric");
+    Assert.areEqual(result.fallback, "funkin");
+
+    Assert.areEqual(result.assets.note.assetPath, "shared:coolstuff");
+    Assert.areEqual(result.assets.note.scale, 1.8);
+    Assert.areEqual(result.assets.note.data.left.prefix, "noteLeft1");
+    Assert.areEqual(result.assets.note.data.down.prefix, "noteDown3");
+    Assert.areEqual(result.assets.note.data.up.prefix, "noteUp2");
+    Assert.areEqual(result.assets.note.data.right.prefix, "noteRight4");
+  }
+
+  @Test
+  public function testFetchEntry()
+  {
+    var result:NoteStyle = NoteStyleRegistry.instance.fetchEntry("test2");
+
+    Assert.areEqual(result.toString(), "NoteStyle(test2)");
+    Assert.areEqual(result.getName(), "Test2");
+    Assert.areEqual(result.getAuthor(), "Eric");
+    Assert.areEqual(result.getFallbackID(), "funkin");
+  }
+
+  @Test
+  public function testFetchBadEntry()
+  {
+    var result:NoteStyle = NoteStyleRegistry.instance.fetchEntry("blablabla");
+
+    Assert.areEqual(result, null);
+  }
+
+  @Test
+  public function testFetchDefault()
+  {
+    var nsrMock:NoteStyleRegistry = mock(NoteStyleRegistry);
+
+    nsrMock.fetchDefault().callsRealMethod();
+
+    // Perform the call.
+    nsrMock.fetchDefault();
+
+    // Verify the underlying call.
+
+    nsrMock.fetchEntry(NoteStyleRegistry.DEFAULT_NOTE_STYLE_ID).verify(times(1));
+  }
+}
diff --git a/tests/unit/source/funkin/play/notes/notestyle/NoteStyleTest.hx b/tests/unit/source/funkin/play/notes/notestyle/NoteStyleTest.hx
new file mode 100644
index 000000000..31e8e38ae
--- /dev/null
+++ b/tests/unit/source/funkin/play/notes/notestyle/NoteStyleTest.hx
@@ -0,0 +1,77 @@
+package funkin.play.notes.notestyle;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.data.notestyle.NoteStyleRegistry;
+import funkin.play.notes.notestyle.NoteStyle;
+import flixel.animation.FlxAnimationController;
+
+@:access(funkin.play.notes.notestyle.NoteStyle)
+class NoteStyleTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass()
+  {
+    NoteStyleRegistry.instance.loadEntries();
+  }
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  @Ignore("This test doesn't work, crashes when the project has 2 mocks of the same class???")
+  public function testBuildNoteSprite()
+  {
+    var target:NoteStyle = NoteStyleRegistry.instance.fetchEntry("funkin");
+
+    var mockNoteSprite:NoteSprite = mock(NoteSprite);
+    // var mockAnim = mock(FlxAnimationController);
+    // mockNoteSprite.animation = mockAnim;
+
+    target.buildNoteSprite(mockNoteSprite);
+
+    Assert.areEqual(mockNoteSprite.frames, []);
+  }
+
+  @Test
+  public function testFallbackBehavior()
+  {
+    var target1:NoteStyle = NoteStyleRegistry.instance.fetchEntry("funkin");
+    var target2:NoteStyle = NoteStyleRegistry.instance.fetchEntry("test2");
+
+    Assert.areEqual("funkin", target1.id);
+    Assert.areEqual("test2", target2.id);
+
+    Assert.areEqual("Funkin'", target1.getName());
+    Assert.areEqual("Test2", target2.getName());
+
+    Assert.isNull(target1.getFallbackID());
+    Assert.areEqual(target1.id, target2.getFallbackID());
+
+    // Overridden fields are different.
+    Assert.areEqual("arrows", target1.getNoteAssetPath(false));
+    Assert.areEqual("coolstuff", target2.getNoteAssetPath(false));
+    
+    Assert.areEqual("shared:arrows", target1.getNoteAssetPath(true));
+    Assert.areEqual("shared:coolstuff", target2.getNoteAssetPath(true));
+
+    // Unspecified fields use the fallback.
+    // Should NOT return null!
+    Assert.areEqual("assets/images/NOTE_hold_assets.png", target1.getHoldNoteAssetPath(false));
+    Assert.areEqual("assets/images/NOTE_hold_assets.png", target2.getHoldNoteAssetPath(false));
+
+    Assert.areEqual("NOTE_hold_assets", target1.getHoldNoteAssetPath(true));
+  }
+}
diff --git a/tests/unit/source/funkin/util/BezierUtilTest.hx b/tests/unit/source/funkin/util/BezierUtilTest.hx
new file mode 100644
index 000000000..90186c111
--- /dev/null
+++ b/tests/unit/source/funkin/util/BezierUtilTest.hx
@@ -0,0 +1,137 @@
+package funkin.util;
+
+import flixel.math.FlxPoint;
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.BezierUtil;
+
+@:access(funkin.util.BezierUtil)
+class BezierUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testBezier2()
+  {
+    var point1:FlxPoint = FlxPoint.get(1, 1);
+    var point2:FlxPoint = FlxPoint.get(2, 2);
+
+    var result:FlxPoint = BezierUtil.bezier2(0.5, point1, point2);
+
+    Assert.areEqual(result.x, 1.5);
+    Assert.areEqual(result.y, 1.5);
+
+    result = BezierUtil.bezier2(0.25, point1, point2);
+
+    Assert.areEqual(result.x, 1.25);
+    Assert.areEqual(result.y, 1.25);
+
+    result = BezierUtil.bezier2(0.75, point1, point2);
+
+    Assert.areEqual(result.x, 1.75);
+    Assert.areEqual(result.y, 1.75);
+  }
+
+  @Test
+  public function testBezier3()
+  {
+    var point1:FlxPoint = FlxPoint.get(1, 1);
+    var point2:FlxPoint = FlxPoint.get(2, 2);
+    var point3:FlxPoint = FlxPoint.get(3, 3);
+
+    var result:FlxPoint = BezierUtil.bezier3(0.5, point1, point2, point3);
+
+    Assert.areEqual(result.x, 2);
+    Assert.areEqual(result.y, 2);
+
+    result = BezierUtil.bezier3(0.25, point1, point2, point3);
+
+    Assert.areEqual(result.x, 1.5);
+    Assert.areEqual(result.y, 1.5);
+
+    result = BezierUtil.bezier3(0.75, point1, point2, point3);
+
+    Assert.areEqual(result.x, 2.5);
+    Assert.areEqual(result.y, 2.5);
+
+    result = BezierUtil.bezier3(0.5, point1, point2, point3);
+
+    Assert.areEqual(result.x, 2);
+    Assert.areEqual(result.y, 2);
+
+    result = BezierUtil.bezier3(0.6, point1, point2, point3);
+
+    Assert.areEqual(result.x, 2.2);
+    Assert.areEqual(result.y, 2.2);
+  }
+
+  @Test
+  public function testBezier4()
+  {
+    var point1:FlxPoint = FlxPoint.get(1, 1);
+    var point2:FlxPoint = FlxPoint.get(2, 2);
+    var point3:FlxPoint = FlxPoint.get(3, 3);
+    var point4:FlxPoint = FlxPoint.get(4, 4);
+
+    var result:FlxPoint = BezierUtil.bezier4(0.5, point1, point2, point3, point4);
+
+    Assert.areEqual(result.x, 2.5);
+    Assert.areEqual(result.y, 2.5);
+
+    result = BezierUtil.bezier4(0.25, point1, point2, point3, point4);
+
+    Assert.areEqual(result.x, 1.75);
+    Assert.areEqual(result.y, 1.75);
+
+    result = BezierUtil.bezier4(0.75, point1, point2, point3, point4);
+
+    Assert.areEqual(result.x, 3.25);
+    Assert.areEqual(result.y, 3.25);
+  }
+
+  @Test
+  public function testBezier5()
+  {
+    var point1:FlxPoint = FlxPoint.get(1, 1);
+    var point2:FlxPoint = FlxPoint.get(2, 2);
+    var point3:FlxPoint = FlxPoint.get(3, 3);
+    var point4:FlxPoint = FlxPoint.get(4, 4);
+    var point5:FlxPoint = FlxPoint.get(5, 5);
+
+    var result:FlxPoint = BezierUtil.bezier5(0.5, point1, point2, point3, point4, point5);
+
+    Assert.areEqual(result.x, 3);
+    Assert.areEqual(result.y, 3);
+
+    result = BezierUtil.bezier5(0.25, point1, point2, point3, point4, point5);
+
+    Assert.areEqual(result.x, 2);
+    Assert.areEqual(result.y, 2);
+
+    result = BezierUtil.bezier5(0.75, point1, point2, point3, point4, point5);
+
+    Assert.areEqual(result.x, 4);
+    Assert.areEqual(result.y, 4);
+
+    result = BezierUtil.bezier5(0.5, point1, point2, point3, point4, point5);
+
+    Assert.areEqual(result.x, 3);
+    Assert.areEqual(result.y, 3);
+  }
+}
diff --git a/tests/unit/source/funkin/util/ClipboardUtilTest.hx b/tests/unit/source/funkin/util/ClipboardUtilTest.hx
new file mode 100644
index 000000000..9efd96d34
--- /dev/null
+++ b/tests/unit/source/funkin/util/ClipboardUtilTest.hx
@@ -0,0 +1,71 @@
+package funkin.util;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.ClipboardUtil;
+
+@:access(funkin.util.ClipboardUtil)
+class ClipboardUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testGetSetClipboard()
+  {
+    var testString = "test string";
+    ClipboardUtil.setClipboard(testString);
+    var clipboardString = ClipboardUtil.getClipboard();
+    Assert.areEqual(testString, clipboardString);
+  }
+
+  @Ignore("This test doesn't work, Lime issue?")
+  @Test
+  public function testAddRemoveListener()
+  {
+    ClipboardUtil.addListener(onClipboardChange);
+
+    var testString = "test string";
+    ClipboardUtil.setClipboard(testString);
+
+    var clipboardString = ClipboardUtil.getClipboard();
+    Assert.areEqual(testString, clipboardString);
+
+    step();
+
+    // TODO: Fix issue where this test fails
+    Assert.areEqual(1, count);
+
+    ClipboardUtil.removeListener(onClipboardChange);
+
+    var testString2 = "test string 2";
+    ClipboardUtil.setClipboard(testString2);
+
+    var clipboardString2 = ClipboardUtil.getClipboard();
+    Assert.areEqual(testString2, clipboardString2);
+
+    Assert.areEqual(1, count);
+  }
+
+  var count:Int = 0;
+
+  function onClipboardChange()
+  {
+    count += 1;
+  }
+}
diff --git a/tests/unit/source/funkin/util/DateUtilTest.hx b/tests/unit/source/funkin/util/DateUtilTest.hx
new file mode 100644
index 000000000..c8adb3824
--- /dev/null
+++ b/tests/unit/source/funkin/util/DateUtilTest.hx
@@ -0,0 +1,35 @@
+package funkin.util;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.DateUtil;
+
+@:access(funkin.util.DateUtil)
+class DateUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testGenerateTimestamp()
+  {
+    var date:Date = new Date(2020, 10 - 1, 31, 3, 0, 0);
+    var timestamp:String = DateUtil.generateTimestamp(date);
+    Assert.areEqual("2020-10-31-03-00-00", timestamp);
+  }
+}
diff --git a/tests/unit/source/funkin/util/SerializerUtilTest.hx b/tests/unit/source/funkin/util/SerializerUtilTest.hx
new file mode 100644
index 000000000..d2adc3350
--- /dev/null
+++ b/tests/unit/source/funkin/util/SerializerUtilTest.hx
@@ -0,0 +1,87 @@
+package funkin.util;
+
+import haxe.io.Bytes;
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.SerializerUtil;
+
+typedef FooBar =
+{
+  a:Int,
+  b:Int,
+  c:Int
+};
+
+@:access(funkin.util.SerializerUtil)
+class SerializerUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testToJSON()
+  {
+    var object = {a: 1, b: 2, c: 3};
+    var json = SerializerUtil.toJSON(object);
+    Assert.areEqual('{' + '\n\t"a": 1,' + '\n\t"b": 2,' + '\n\t"c": 3' + '\n}', json);
+  }
+
+  @Test
+  public function testFromJSON()
+  {
+    var json = '{' + '\n\t"a": 1,' + '\n\t"b": 2,' + '\n\t"c": 3' + '\n}';
+    var object = SerializerUtil.fromJSON(json);
+    Assert.areEqual(1, object.a);
+    Assert.areEqual(2, object.b);
+    Assert.areEqual(3, object.c);
+  }
+
+  @Test
+  public function testFromJSONBytes()
+  {
+    var json = '{' + '\n\t"a": 1,' + '\n\t"b": 2,' + '\n\t"c": 3' + '\n}';
+    var bytes = Bytes.ofString(json);
+
+    var object = SerializerUtil.fromJSONBytes(bytes);
+    Assert.areEqual(1, object.a);
+    Assert.areEqual(2, object.b);
+    Assert.areEqual(3, object.c);
+  }
+
+  @Test
+  public function testReplacer()
+  {
+    var version:thx.semver.Version = '1.0.0-beta';
+
+    Assert.areEqual(1, version.major);
+    Assert.areEqual(0, version.minor);
+    Assert.areEqual(0, version.patch);
+    Assert.areEqual(true, version.hasPre);
+    Assert.areEqual('beta', version.pre);
+    // Assert.areEqual(false, version.hasBuild);
+    Assert.areEqual('', version.build);
+
+    var formatted = SerializerUtil.replacer('version', version);
+
+    Assert.areEqual('1.0.0-beta', formatted);
+
+    var test2 = SerializerUtil.toJSON({version: version});
+
+    Assert.areEqual('{' + '\n\t"version": "1.0.0-beta"' + '\n}', test2);
+  }
+}
diff --git a/tests/unit/source/funkin/util/SortUtilTest.hx b/tests/unit/source/funkin/util/SortUtilTest.hx
new file mode 100644
index 000000000..4720c3da6
--- /dev/null
+++ b/tests/unit/source/funkin/util/SortUtilTest.hx
@@ -0,0 +1,63 @@
+package funkin.util;
+
+import flixel.FlxObject;
+import flixel.FlxSprite;
+import flixel.util.FlxSort;
+import funkin.play.song.SongData.SongNoteData;
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.SortUtil;
+
+@:access(funkin.util.SortUtil)
+class SortUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testAlphabetically()
+  {
+    var arr:Array<String> = ["b", "a", "c"];
+
+    arr.sort(SortUtil.alphabetically);
+
+    Assert.areEqual(["a", "b", "c"], arr);
+  }
+
+  @Test
+  public function testByZIndex()
+  {
+    var arr:Array<FlxObject> = [new FlxSprite(), new FlxObject(), new FlxSprite()];
+
+    arr[0].zIndex = 2000;
+    arr[1].zIndex = 1000;
+    arr[2].zIndex = 3000;
+
+    arr.sort(SortUtil.byZIndex.bind(FlxSort.ASCENDING));
+
+    Assert.areEqual(1000, arr[0].zIndex);
+    Assert.areEqual(2000, arr[1].zIndex);
+    Assert.areEqual(3000, arr[2].zIndex);
+
+    arr.sort(SortUtil.byZIndex.bind(FlxSort.DESCENDING));
+
+    Assert.areEqual(3000, arr[0].zIndex);
+    Assert.areEqual(2000, arr[1].zIndex);
+    Assert.areEqual(1000, arr[2].zIndex);
+  }
+}
diff --git a/tests/unit/source/funkin/util/VersionUtilTest.hx b/tests/unit/source/funkin/util/VersionUtilTest.hx
new file mode 100644
index 000000000..55848955a
--- /dev/null
+++ b/tests/unit/source/funkin/util/VersionUtilTest.hx
@@ -0,0 +1,64 @@
+package funkin.util;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.VersionUtil;
+
+@:access(funkin.util.VersionUtil)
+class VersionUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testValidateVersionStr()
+  {
+    Assert.areEqual(true, VersionUtil.validateVersionStr("1.0.0", "1.0.0"));
+
+    Assert.areEqual(false, VersionUtil.validateVersionStr("ehe", "test"));
+  }
+
+  @Test
+  public function testValidateVersion()
+  {
+    var version:thx.semver.Version = "1.0.0"; // implicit cast
+    var versionRule:thx.semver.VersionRule = "1.0.0"; // implicit cast
+
+    Assert.areEqual(true, VersionUtil.validateVersion(version, versionRule));
+
+    var versionRule2:thx.semver.VersionRule = ">=3.1.0"; // implicit cast
+
+    var version1:thx.semver.Version = "3.0.0";
+    var version2:thx.semver.Version = "3.1.1";
+    var version3:thx.semver.Version = "4.2.0";
+
+    Assert.areEqual(false, VersionUtil.validateVersion(version1, versionRule2));
+    Assert.areEqual(true, VersionUtil.validateVersion(version2, versionRule2));
+    Assert.areEqual(true, VersionUtil.validateVersion(version3, versionRule2));
+  }
+
+  @Test
+  public function testGetVersionFromJSON()
+  {
+    var jsonStr:String = "{ \"version\": \"3.1.0\" }";
+
+    var version:thx.semver.Version = VersionUtil.getVersionFromJSON(jsonStr);
+
+    Assert.areEqual("3.1.0", version.toString());
+  }
+}
diff --git a/tests/unit/source/funkin/util/assets/DataAssetsTest.hx b/tests/unit/source/funkin/util/assets/DataAssetsTest.hx
new file mode 100644
index 000000000..7612d4706
--- /dev/null
+++ b/tests/unit/source/funkin/util/assets/DataAssetsTest.hx
@@ -0,0 +1,42 @@
+package funkin.util.assets;
+
+import openfl.utils.Assets;
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.assets.DataAssets;
+
+@:access(funkin.util.assets.DataAssets)
+class DataAssetsTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testBuildDataPath()
+  {
+    Assert.areEqual('assets/data/test.json', DataAssets.buildDataPath('test.json'));
+  }
+
+  @Test
+  public function listDataFilesInPath()
+  {
+    var expected = ['blablabla', 'test1', 'test2'];
+
+    Assert.areEqual(expected, DataAssets.listDataFilesInPath('test/'));
+  }
+}
diff --git a/tests/unit/source/funkin/util/assets/FlxAnimationUtilTest.hx b/tests/unit/source/funkin/util/assets/FlxAnimationUtilTest.hx
new file mode 100644
index 000000000..990d998f2
--- /dev/null
+++ b/tests/unit/source/funkin/util/assets/FlxAnimationUtilTest.hx
@@ -0,0 +1,118 @@
+package funkin.util.assets;
+
+import funkin.util.assets.FlxAnimationUtil;
+import flixel.animation.FlxAnimationController;
+import funkin.data.animation.AnimationData;
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.DateUtil;
+import flixel.FlxSprite;
+
+@:access(funkin.util.assets.FlxAnimationUtil)
+class FlxAnimationUtilTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testAddAtlasAnimation()
+  {
+    // Build a mock child class of FlxSprite
+    var mockSprite = mock(FlxSprite);
+    var mockAnim = mock(FlxAnimationController);
+    mockSprite.animation = mockAnim;
+
+    var animData:AnimationData =
+      {
+        name: "testAnim",
+        prefix: "blablabla"
+      };
+
+    FlxAnimationUtil.addAtlasAnimation(mockSprite, animData);
+
+    // Verify that the method was called once.
+    // If not, a VerificationException will be thrown and the test will fail.
+    mockAnim.addByPrefix("testAnim", "blablabla", 24, false, false, false).verify(times(1));
+
+    // Verify there were no other functions called.
+    mockAnim.verifyZeroInteractions();
+    mockSprite.verifyZeroInteractions();
+
+    var animData2:AnimationData =
+      {
+        name: "testAnim2",
+        prefix: "blablabla2",
+        frameIndices: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
+        frameRate: 12,
+        flipX: true,
+        flipY: true,
+        looped: true
+      };
+
+    FlxAnimationUtil.addAtlasAnimation(mockSprite, animData2);
+
+    try
+    {
+      mockAnim.addByIndices("testAnim2", "blablabla2", cast anyIterator, "", 12, true, true, true).verify(times(1));
+    }
+    catch (e)
+    {
+      trace('CAUGHT EXCEPTION');
+      trace(e);
+    }
+
+    mockAnim.verifyZeroInteractions();
+    mockSprite.verifyZeroInteractions();
+  }
+
+  @Test
+  public function testAddAtlasAnimations()
+  {
+    // Build a mock child class of FlxSprite
+    var mockSprite = mock(FlxSprite);
+    var mockAnim = mock(FlxAnimationController);
+    mockSprite.animation = mockAnim;
+
+    var animData:Array<AnimationData> = [
+      {
+        name: "testAnim",
+        prefix: "blablabla"
+      },
+      {
+        name: "testAnim2",
+        prefix: "blablabla2"
+      },
+      {
+        name: "testAnim3",
+        prefix: "blablabla3"
+      }
+    ];
+
+    FlxAnimationUtil.addAtlasAnimations(mockSprite, animData);
+
+    // Verify that the method was called once.
+    // If not, a VerificationException will be thrown and the test will fail.
+    mockAnim.addByPrefix("testAnim", "blablabla", 24, false, false, false).verify(times(1));
+    mockAnim.addByPrefix("testAnim2", "blablabla2", 24, false, false, false).verify(times(1));
+    mockAnim.addByPrefix("testAnim3", "blablabla3", 24, false, false, false).verify(times(1));
+
+    // Verify there were no other functions called.
+    mockAnim.verifyZeroInteractions();
+    mockSprite.verifyZeroInteractions();
+  }
+}
diff --git a/tests/unit/source/funkin/util/tools/ArraySortToolsTest.hx b/tests/unit/source/funkin/util/tools/ArraySortToolsTest.hx
new file mode 100644
index 000000000..0bcef00b5
--- /dev/null
+++ b/tests/unit/source/funkin/util/tools/ArraySortToolsTest.hx
@@ -0,0 +1,165 @@
+package funkin.util.tools;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.tools.ArrayTools;
+
+@:access(funkin.util.tools.ArrayTools)
+class ArraySortToolsTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testMergeSort()
+  {
+    var testArray:Array<Int> = [5, 4, 3, 2, 1];
+
+    function compare(a:Int, b:Int)
+    {
+      return a - b;
+    }
+
+    ArraySortTools.mergeSort(testArray, compare);
+
+    Assert.areEqual(testArray[0], 1);
+    Assert.areEqual(testArray[1], 2);
+    Assert.areEqual(testArray[2], 3);
+    Assert.areEqual(testArray[3], 4);
+    Assert.areEqual(testArray[4], 5);
+
+    var testArray2:Array<Int> = [9, 6, 3, 12];
+
+    ArraySortTools.mergeSort(testArray2, compare);
+
+    Assert.areEqual(testArray2[0], 3);
+    Assert.areEqual(testArray2[1], 6);
+    Assert.areEqual(testArray2[2], 9);
+    Assert.areEqual(testArray2[3], 12);
+
+    // Just make sure these don't crash.
+    ArraySortTools.mergeSort([], compare);
+    ArraySortTools.mergeSort(null, compare);
+    ArraySortTools.mergeSort([], null);
+    ArraySortTools.mergeSort(null, null);
+
+    // Make sure these throw an exception.
+    try
+    {
+      ArraySortTools.mergeSort(testArray, null);
+
+      Assert.fail("Function should have thrown an exception.");
+    }
+    catch (e)
+    {
+      Assert.areEqual("No comparison function provided.", e);
+    }
+  }
+
+  @Test
+  public function testQuickSort()
+  {
+    var testArray:Array<Int> = [5, 4, 3, 2, 1];
+
+    function compare(a:Int, b:Int)
+    {
+      return a - b;
+    }
+
+    ArraySortTools.quickSort(testArray, compare);
+
+    Assert.areEqual(testArray[0], 1);
+    Assert.areEqual(testArray[1], 2);
+    Assert.areEqual(testArray[2], 3);
+    Assert.areEqual(testArray[3], 4);
+    Assert.areEqual(testArray[4], 5);
+
+    var testArray2:Array<Int> = [9, 6, 3, 12];
+
+    ArraySortTools.quickSort(testArray2, compare);
+
+    Assert.areEqual(testArray2[0], 3);
+    Assert.areEqual(testArray2[1], 6);
+    Assert.areEqual(testArray2[2], 9);
+    Assert.areEqual(testArray2[3], 12);
+
+    // Just make sure these don't crash.
+    ArraySortTools.quickSort([], compare);
+    ArraySortTools.quickSort(null, compare);
+    ArraySortTools.quickSort([], null);
+    ArraySortTools.quickSort(null, null);
+
+    // Make sure these throw an exception.
+    try
+    {
+      ArraySortTools.quickSort(testArray, null);
+
+      Assert.fail("Function should have thrown an exception.");
+    }
+    catch (e)
+    {
+      Assert.areEqual("No comparison function provided.", e);
+    }
+  }
+
+  @Test
+  public function testInsertionSort()
+  {
+    var testArray:Array<Int> = [5, 4, 3, 2, 1];
+
+    function compare(a:Int, b:Int)
+    {
+      return a - b;
+    }
+
+    ArraySortTools.insertionSort(testArray, compare);
+
+    Assert.areEqual(testArray[0], 1);
+    Assert.areEqual(testArray[1], 2);
+    Assert.areEqual(testArray[2], 3);
+    Assert.areEqual(testArray[3], 4);
+    Assert.areEqual(testArray[4], 5);
+
+    var testArray2:Array<Int> = [9, 6, 3, 12];
+
+    ArraySortTools.insertionSort(testArray2, compare);
+
+    Assert.areEqual(testArray2[0], 3);
+    Assert.areEqual(testArray2[1], 6);
+    Assert.areEqual(testArray2[2], 9);
+    Assert.areEqual(testArray2[3], 12);
+
+    // Just make sure these don't crash.
+    ArraySortTools.insertionSort([], compare);
+    ArraySortTools.insertionSort(null, compare);
+    ArraySortTools.insertionSort([], null);
+    ArraySortTools.insertionSort(null, null);
+
+    // Make sure these throw an exception.
+    try
+    {
+      ArraySortTools.insertionSort(testArray, null);
+
+      Assert.fail("Function should have thrown an exception.");
+    }
+    catch (e)
+    {
+      Assert.areEqual("No comparison function provided.", e);
+    }
+  }
+}
diff --git a/tests/unit/source/funkin/util/tools/ArrayToolsTest.hx b/tests/unit/source/funkin/util/tools/ArrayToolsTest.hx
new file mode 100644
index 000000000..68adb833b
--- /dev/null
+++ b/tests/unit/source/funkin/util/tools/ArrayToolsTest.hx
@@ -0,0 +1,65 @@
+package funkin.util.tools;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.tools.ArrayTools;
+
+@:access(funkin.util.tools.ArrayTools)
+class ArrayToolsTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testUnique()
+  {
+    var testArray:Array<Int> = [1, 2, 3, 4, 5, 6, 10, 7, 8, 9, 3, 4, 5, 6, 11, 7, 8];
+
+    var uniqueArray:Array<Int> = ArrayTools.unique(testArray);
+
+    Assert.areEqual(uniqueArray.length, 11);
+
+    // Array order doesn't change
+    Assert.areEqual(uniqueArray[0], 1);
+    Assert.areEqual(uniqueArray[1], 2);
+    Assert.areEqual(uniqueArray[2], 3);
+    Assert.areEqual(uniqueArray[3], 4);
+    Assert.areEqual(uniqueArray[4], 5);
+    Assert.areEqual(uniqueArray[5], 6);
+    Assert.areEqual(uniqueArray[6], 10);
+    Assert.areEqual(uniqueArray[7], 7);
+    Assert.areEqual(uniqueArray[8], 8);
+    Assert.areEqual(uniqueArray[9], 9);
+    Assert.areEqual(uniqueArray[10], 11);
+  }
+
+  @Test
+  public function testFind()
+  {
+    function predicate(a:String):Bool
+    {
+      return a.startsWith("Hello");
+    }
+
+    var testArray:Array<String> = ["Foo", "Bar", "HelloWorld", "Baz", "HelloTest"];
+
+    var result = ArrayTools.find(testArray, predicate);
+
+    Assert.areEqual(result, "HelloWorld");
+  }
+}
diff --git a/tests/unit/source/funkin/util/tools/IteratorToolsTest.hx b/tests/unit/source/funkin/util/tools/IteratorToolsTest.hx
new file mode 100644
index 000000000..deaea352b
--- /dev/null
+++ b/tests/unit/source/funkin/util/tools/IteratorToolsTest.hx
@@ -0,0 +1,59 @@
+package funkin.util.tools;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.tools.IteratorTools;
+
+@:access(funkin.util.tools.IteratorTools)
+class IteratorToolsTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testArray()
+  {
+    var iter = new MyStringIterator("HelloWorld");
+
+    var arr = IteratorTools.array(iter);
+
+    Assert.areEqual(["H", "e", "l", "l", "o", "W", "o", "r", "l", "d"], arr);
+  }
+}
+
+class MyStringIterator
+{
+  var s:String;
+  var i:Int;
+
+  public function new(s:String)
+  {
+    this.s = s;
+    i = 0;
+  }
+
+  public function hasNext()
+  {
+    return i < s.length;
+  }
+
+  public function next()
+  {
+    return s.charAt(i++);
+  }
+}
diff --git a/tests/unit/source/funkin/util/tools/MapToolsTest.hx b/tests/unit/source/funkin/util/tools/MapToolsTest.hx
new file mode 100644
index 000000000..c3fe34461
--- /dev/null
+++ b/tests/unit/source/funkin/util/tools/MapToolsTest.hx
@@ -0,0 +1,55 @@
+package funkin.util.tools;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.tools.MapTools;
+
+@:access(funkin.util.tools.MapTools)
+class MapToolsTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testSize()
+  {
+    var testMap:Map<String, String> = ["key1" => "value1", "key2" => "value2", "key3" => "value3"];
+
+    Assert.areEqual(3, MapTools.size(testMap));
+  }
+
+  @Test
+  public function testValues()
+  {
+    var testMap:Map<String, String> = ["key1" => "value1", "key2" => "value2", "key3" => "value3"];
+
+    var result:Array<String> = MapTools.values(testMap);
+    result.sort(SortUtil.alphabetically);
+    Assert.areEqual(["value1", "value2", "value3"], result);
+  }
+
+  @Test
+  public function testKeyValues()
+  {
+    var testMap:Map<String, String> = ["key1" => "value1", "key2" => "value2", "key3" => "value3"];
+
+    var result:Array<String> = MapTools.keyValues(testMap);
+    result.sort(SortUtil.alphabetically);
+    Assert.areEqual(["key1", "key2", "key3"], result);
+  }
+}
diff --git a/tests/unit/source/funkin/util/tools/StringToolsTest.hx b/tests/unit/source/funkin/util/tools/StringToolsTest.hx
new file mode 100644
index 000000000..215b5e402
--- /dev/null
+++ b/tests/unit/source/funkin/util/tools/StringToolsTest.hx
@@ -0,0 +1,59 @@
+package funkin.util.tools;
+
+import massive.munit.util.Timer;
+import massive.munit.Assert;
+import massive.munit.async.AsyncFactory;
+import funkin.util.tools.StringTools;
+
+@:access(funkin.util.tools.StringTools)
+class StringToolsTest extends FunkinTest
+{
+  public function new()
+  {
+    super();
+  }
+
+  @BeforeClass
+  public function beforeClass() {}
+
+  @AfterClass
+  public function afterClass() {}
+
+  @Before
+  public function setup() {}
+
+  @After
+  public function tearDown() {}
+
+  @Test
+  public function testToTitleCase()
+  {
+    var input = "hello world";
+
+    Assert.areEqual("Hello World", StringTools.toTitleCase(input));
+  }
+
+  @Test
+  public function testToLowerKebabCase()
+  {
+    var input = "hello world";
+
+    Assert.areEqual("hello-world", StringTools.toLowerKebabCase(input));
+  }
+
+  @Test
+  public function testToUpperKebabCase()
+  {
+    var input = "hello world";
+
+    Assert.areEqual("HELLO-WORLD", StringTools.toUpperKebabCase(input));
+  }
+
+  @Test
+  public function testParseJSON()
+  {
+    var input = "{ \"hello\": \"world\" }";
+
+    Assert.areEqual({hello: "world"}, StringTools.parseJSON(input));
+  }
+}
diff --git a/tests/unit/source/import.hx b/tests/unit/source/import.hx
new file mode 100644
index 000000000..89264c0c9
--- /dev/null
+++ b/tests/unit/source/import.hx
@@ -0,0 +1,21 @@
+#if !macro
+// Only import these when we aren't in a macro.
+import funkin.util.Constants;
+import funkin.Paths;
+import flixel.FlxG; // This one in particular causes a compile error if you're using macros.
+
+// These are great.
+using Lambda;
+using StringTools;
+using funkin.util.tools.ArrayTools;
+using funkin.util.tools.ArraySortTools;
+using funkin.util.tools.IteratorTools;
+using funkin.util.tools.MapTools;
+using funkin.util.tools.StringTools;
+#end
+
+// Testing-specific
+// Mocking
+import mockatoo.Mockatoo.*;
+
+using mockatoo.Mockatoo;
diff --git a/tests/unit/start-mac-native.sh b/tests/unit/start-mac-native.sh
new file mode 100755
index 000000000..fb6c812bd
--- /dev/null
+++ b/tests/unit/start-mac-native.sh
@@ -0,0 +1,3 @@
+#!/bin/zsh
+
+haxe test-cpp.hxml
diff --git a/tests/unit/start-mac-web.sh b/tests/unit/start-mac-web.sh
new file mode 100755
index 000000000..66af469f7
--- /dev/null
+++ b/tests/unit/start-mac-web.sh
@@ -0,0 +1,3 @@
+#!/bin/zsh
+
+haxe test-web.hxml
diff --git a/tests/unit/start-win-native.bat b/tests/unit/start-win-native.bat
new file mode 100644
index 000000000..7678a86ea
--- /dev/null
+++ b/tests/unit/start-win-native.bat
@@ -0,0 +1,3 @@
+REM Launches the unit tests for the native target on Windows.
+
+haxe test-cpp.hxml
diff --git a/tests/unit/test-cpp.hxml b/tests/unit/test-cpp.hxml
new file mode 100644
index 000000000..9379f841d
--- /dev/null
+++ b/tests/unit/test-cpp.hxml
@@ -0,0 +1,11 @@
+# Updates TestSuite.hx to include all tests
+#-cmd haxelib run munit gen
+# Actually performs the tests
+#-cmd haxelib run munit test -debug -coverage
+# -debug may or may not be needed
+# -coverage adds code coverage reporting
+
+# Legacy style. Doesn't give detailed coverage reports,
+# but it works without crashing.
+-cmd haxelib run munit gen
+-cmd haxelib run lime test cpp
diff --git a/tests/unit/test-web.hxml b/tests/unit/test-web.hxml
new file mode 100644
index 000000000..c7c2ab444
--- /dev/null
+++ b/tests/unit/test-web.hxml
@@ -0,0 +1,5 @@
+# Update the test runner classes
+# TODO: This just opens the browser and doesn't do anything?
+-cmd haxelib run munit gen
+-cmd haxelib run lime build html5
+-cmd haxelib run lime test html5
diff --git a/tests/unit/test.hxml b/tests/unit/test.hxml
new file mode 100644
index 000000000..cece0c43a
--- /dev/null
+++ b/tests/unit/test.hxml
@@ -0,0 +1,32 @@
+## CPP
+--next
+-main TestMain
+-cpp build/cpp_test
+# Funkin' deps
+-lib lime
+-lib openfl
+-lib flixel
+-lib flixel-addons
+-lib flixel-ui
+-lib hscript
+-lib polymod
+-lib haxeui-core
+-lib haxeui-flixel
+-lib flxanimate
+-lib hxCodec
+-lib thx.semver
+-lib json2object
+-lib tink_json
+# Test deps
+-lib munit
+-lib hamcrest
+-lib mcover
+-lib mockatoo
+# Class paths
+-cp source
+-cp ../../source
+# Flixel macros
+--remap flash:openfl
+--macro flixel.system.macros.FlxDefines.run()
+# Funkin' macros
+--macro addMetadata('@:build(funkin.util.macro.FlxMacro.buildFlxBasic())', 'flixel.FlxBasic')
diff --git a/tests/unit/test.hxml-old b/tests/unit/test.hxml-old
new file mode 100644
index 000000000..d86661fc8
--- /dev/null
+++ b/tests/unit/test.hxml-old
@@ -0,0 +1,24 @@
+## JavaScript HTML5
+--next
+-js build/js_test.js
+# Funkin' deps
+-lib lime
+-lib openfl
+-lib flixel
+-lib flixel-addons
+-lib hscript
+-lib flixel-ui
+-lib haxeui-core
+-lib haxeui-flixel
+-lib polymod
+-lib flxanimate
+-lib hxCodec
+-lib thx.semver
+-lib json2object
+-lib tink_json
+# Test deps
+-lib munit
+-lib hamcrest
+# Class paths
+-cp source
+-cp ../../source