This is really fun! I like the idea and hope you plan to develop it further! I was initially a little confused in the second level when I tried to flip gravity by shooting and it didn't work. Unfortunately, you'd taught me in the first level that shooting = gravity flip, not shooting at the target = gravity flip. It can be really hard to communicate with the player; don't give up!
I also love the splash screen you made for the itch page. It's a clever bit of graphic design.