diff --git a/src/LocalLevelLoader.hx b/src/LocalLevelLoader.hx
new file mode 100644
index 00000000..b9c93e72
--- /dev/null
+++ b/src/LocalLevelLoader.hx
@@ -0,0 +1,95 @@
+package src;
+
+import haxe.io.Bytes;
+import haxe.io.Path;
+import mis.MisParser;
+import src.Mission;
+import src.ResourceLoader;
+import src.MarbleGame;
+import src.Console;
+
+class LocalLevelLoader {
+	public static var currentLocalPath:String = null;
+	public static var currentMission:Mission = null;
+
+	public static function init() {
+		#if js
+		setupWebPostMessage();
+		notifyReady();
+		#end
+	}
+
+	public static function notifyReady() {
+		#if js
+		if (js.Browser.window.opener != null) {
+			try {
+				Console.log("Notifying level editor that MBHaxe is ready...");
+				js.Browser.window.opener.postMessage({ type: "mbhaxe-ready" }, "*");
+			} catch (e:Dynamic) {}
+		}
+		try {
+			var channel = new js.html.BroadcastChannel("mbhaxe-level-editor");
+			channel.postMessage({ type: "mbhaxe-ready" });
+		} catch (e:Dynamic) {}
+		#end
+	}
+
+	static function setupWebPostMessage() {
+		#if js
+		function handleMessage(data:Dynamic) {
+			if (data == null || data.type != "loadLevel" || data.files == null) return;
+			Console.log("Received level load message via postMessage/BroadcastChannel");
+
+			var mission:Mission = null;
+
+			var filesAccess:haxe.DynamicAccess<Dynamic> = data.files;
+			for (k in filesAccess.keys()) {
+				var fileData:Dynamic = filesAccess.get(k);
+				var bytes:Bytes = null;
+				if (Std.isOfType(fileData, String)) {
+					bytes = Bytes.ofString(fileData);
+				} else {
+					bytes = Bytes.ofData(fileData);
+				}
+				ResourceLoader.registerLocalFile(k, bytes);
+
+				if (StringTools.endsWith(k.toLowerCase(), ".mis")) {
+					mission = createLocalMission(k, bytes.toString());
+				}
+			}
+
+			if (mission == null) {
+				Console.error("postMessage loadLevel missing .mis file in files payload");
+				return;
+			}
+
+			MarbleGame.instance.playMission(mission);
+		}
+
+		js.Browser.window.addEventListener("message", (e:js.html.MessageEvent) -> {
+			handleMessage(e.data);
+		});
+
+		try {
+			var channel = new js.html.BroadcastChannel("mbhaxe-level-editor");
+			channel.onmessage = (e:js.html.MessageEvent) -> {
+				handleMessage(e.data);
+			};
+		} catch (e:Dynamic) {}
+		#end
+	}
+
+	public static function createLocalMission(misRelPath:String, misText:String):Mission {
+		var misParser = new MisParser(misText);
+		var parsed = misParser.parse();
+		var mInfo = misParser.parseMissionInfo();
+
+		var mission = Mission.fromMissionInfo(misRelPath, mInfo);
+		mission.isCustom = true;
+		mission.isLocal = true;
+		mission.game = mInfo.game?.toLowerCase();
+
+		currentMission = mission;
+		return mission;
+	}
+}
\ No newline at end of file
diff --git a/src/Main.hx b/src/Main.hx
index 72c8b48d..6ab75267 100644
--- a/src/Main.hx
+++ b/src/Main.hx
@@ -7,6 +7,7 @@ import src.Console;
 import hxd.Key;
 import src.Util;
 import src.ResourceLoader;
+import src.LocalLevelLoader;
 #if js
 import fs.ManifestFileSystem;
 import fs.ManifestBuilder;
@@ -108,6 +109,7 @@ class Main extends hxd.App {
 
 				new ProfilerUI(s2d);
 
+				LocalLevelLoader.init();
 				loaded = true;
 			});
 		} catch (e) {
diff --git a/src/Mission.hx b/src/Mission.hx
index 62b7b6d1..45e4e138 100644
--- a/src/Mission.hx
+++ b/src/Mission.hx
@@ -41,6 +41,7 @@ class Mission {
 	public var game:String;
 	public var hasEgg:Bool;
 	public var isCustom:Bool;
+	public var isLocal:Bool = false;
 	public var gameMode:String;
 	#if hl
 	public var addedAt:Int64;
@@ -237,6 +238,10 @@ class Mission {
 		#end
 		if (!StringTools.endsWith(path, ".dif"))
 			path += ".dif";
+		if (ResourceLoader.existsInZip(path))
+			return path;
+		if (ResourceLoader.existsInZip(fname))
+			return fname;
 		if (ResourceLoader.exists(path))
 			return path;
 		if (StringTools.contains(path, 'interiors_mbg/'))
@@ -254,6 +259,8 @@ class Mission {
 		path = StringTools.replace(path, "lbinteriors", "interiors"); // This shit ew
 		if (ResourceLoader.exists(path))
 			return path;
+		if (ResourceLoader.exists(fname))
+			return fname;
 		Console.error("Interior resource not found: " + rawElementPath);
 		return "";
 	}
diff --git a/src/ResourceLoader.hx b/src/ResourceLoader.hx
index 7cae151d..9e8be8aa 100644
--- a/src/ResourceLoader.hx
+++ b/src/ResourceLoader.hx
@@ -283,10 +283,16 @@ class ResourceLoader {
 		#if (js || android)
 		path = StringTools.replace(path, "data/", "");
 		#end
+		if (ResourceLoader.existsInZip(path))
+			return path;
+		if (ResourceLoader.existsInZip(fname))
+			return fname;
 		if (ResourceLoader.exists(path))
 			return path;
 		if (ResourceLoader.exists(dirpath + fname))
 			return dirpath + fname;
+		if (ResourceLoader.exists(fname))
+			return fname;
 		return "";
 	}
 
@@ -553,6 +559,13 @@ class ResourceLoader {
 		return fileSystem.exists(path);
 	}
 
+	public static function existsInZip(path:String):Bool {
+		#if (js || android)
+		path = StringTools.replace(path, "data/", "");
+		#end
+		return zipFilesystem.exists(path.toLowerCase());
+	}
+
 	public static function clearInteriorResources() {
 		interiorResources = new Map();
 	}
@@ -610,4 +623,13 @@ class ResourceLoader {
 			zipFilesystem.set(fname, zfe);
 		}
 	}
+
+	public static function registerLocalFile(path:String, bytes:haxe.io.Bytes) {
+		path = StringTools.replace(path, "\\", "/").toLowerCase();
+		#if (js || android)
+		path = StringTools.replace(path, "data/", "");
+		#end
+		var zfe = new BytesFileEntry(path, bytes);
+		zipFilesystem.set(path, zfe);
+	}
 }
diff --git a/src/gui/EndGameGui.hx b/src/gui/EndGameGui.hx
index cc293be8..c56ee2d7 100644
--- a/src/gui/EndGameGui.hx
+++ b/src/gui/EndGameGui.hx
@@ -396,7 +396,7 @@ class EndGameGui extends GuiControl {
 		var rewindUsed = MarbleGame.instance.world.rewindUsed;
 		var cheatsUsed = MarbleGame.instance.world.cheatsUsed;
 
-		if (idx <= 4) {
+		if (idx <= 4 && !mission.isLocal) {
 			setButtonStates(false);
 			var end = new EnterNameDlg(idx, (name) -> {
 				setButtonStates(true);
@@ -440,7 +440,7 @@ class EndGameGui extends GuiControl {
 				scoreSubmitted = true;
 			});
 			this.addChild(end);
-		} else {
+		} else if (!mission.isLocal) {
 			// Check if we can submit LB scores
 			var lbPath = mission.path;
 			if (mission.isClaMission)