Hey~
I thought that the idea of a button that changes everything to be really neat, it definitely added a new dimension to the game that I really enjoyed.
I wish there was more to do than just point and shoot at big enemies, maybe something like a powerup or a different kind of enemy would have really spiced things up. Changing environments was really cool but there wasn't really anything different about them except for the skin.
That said, I do understand the restraints of a game jam and am really impressed with what you've made. I had a lot of fun and the mechanics that are here are super solid.