diff --git a/source/funkin/modding/PolymodHandler.hx b/source/funkin/modding/PolymodHandler.hx
index c352aa606..c5dfcdca3 100644
--- a/source/funkin/modding/PolymodHandler.hx
+++ b/source/funkin/modding/PolymodHandler.hx
@@ -251,6 +251,10 @@ class PolymodHandler
     // Lib.load() can load malicious DLLs
     Polymod.blacklistImport('cpp.Lib');
 
+    // `Unserializer`
+    // Unserializerr.DEFAULT_RESOLVER.resolveClass() can access blacklisted packages
+    Polymod.blacklistImport('Unserializer');
+
     // `polymod.*`
     // You can probably unblacklist a module
     for (cls in ClassMacro.listClassesInPackage('polymod'))
diff --git a/source/funkin/play/PlayState.hx b/source/funkin/play/PlayState.hx
index e7096b2e2..a51635212 100644
--- a/source/funkin/play/PlayState.hx
+++ b/source/funkin/play/PlayState.hx
@@ -578,7 +578,6 @@ class PlayState extends MusicBeatSubState
 
   // TODO: Refactor or document
   var generatedMusic:Bool = false;
-  var perfectMode:Bool = false;
 
   static final BACKGROUND_COLOR:FlxColor = FlxColor.BLACK;
 
@@ -2535,12 +2534,6 @@ class PlayState extends MusicBeatSubState
    */
   function debugKeyShit():Void
   {
-    #if !debug
-    perfectMode = false;
-    #else
-    if (FlxG.keys.justPressed.H) camHUD.visible = !camHUD.visible;
-    #end
-
     #if CHART_EDITOR_SUPPORTED
     // Open the stage editor overlaying the current state.
     if (controls.DEBUG_STAGE)
@@ -2572,6 +2565,9 @@ class PlayState extends MusicBeatSubState
     #end
 
     #if (debug || FORCE_DEBUG_VERSION)
+    // H: Hide the HUD.
+    if (FlxG.keys.justPressed.H) camHUD.visible = !camHUD.visible;
+
     // 1: End the song immediately.
     if (FlxG.keys.justPressed.ONE) endSong(true);
 
diff --git a/source/funkin/play/song/Song.hx b/source/funkin/play/song/Song.hx
index 91d35d8fa..147923add 100644
--- a/source/funkin/play/song/Song.hx
+++ b/source/funkin/play/song/Song.hx
@@ -277,7 +277,7 @@ class Song implements IPlayStateScriptedClass implements IRegistryEntry<SongMeta
       // If there are no difficulties in the metadata, there's a problem.
       if (metadata.playData.difficulties.length == 0)
       {
-        throw 'Song $id has no difficulties listed in metadata!';
+        trace('[WARN] Song $id has no difficulties listed in metadata!');
       }
 
       // There may be more difficulties in the chart file than in the metadata,