Very cool idea, the execution is a bit rough around the edges, but that's to be expected. My old laptop struggled with it a bit. It was surprisingly difficult from the get go. You might want to add some platforms where I can safely switch between worlds without falling off early on while I'm still learning the ropes, so I don't have to memorize the placement of everything and can focus on acclimatizing myself with both the controls and the concept. (Granted, I didn't go very far, so it could be that you have these spots later in the level.)
I really liked the music, although it was a bit at odds with the visuals. UI, GFX could use a bit more work, but it's very solid overall, well done!