You should enable fullscreen view for this game, as the mouse keeps going off viewport while playing! You can do this post-jam from the edit project page.
This is a simple, but really fun concept. Good use of the theme. I see you went for the cross dimensional bonus challenge, which is nice to see. They can make for very unique looking games.
Moving forward, I'd change the background from the default. The difficulty between levels (you should number them) varies a lot. The screen went red and stayed that way.