I know you just said you don't want to add on to the game but maybe you could add a level editor? (I know you just said you would release the source code and this is very unlikely it would be cool!)
Level editors are a lot more complicated to make than many people realize (this is my first game made with Godot) and I'd rather work on my own ideas. Plus, if you have a copy of Pizza Tower, there's AFOM to make your own Mini-Noise-centered levels.