I like this a lot! Love the aesthetic and I think the gameplay loop has a lot of potential. If you want to keep working on this, it would be cool if the level actually added/deleted sections rather than just altering between a few shapes. Like an amoeba or something...if that makes sense :P
if there is one bit of constructive criticism I could add: I feel like there's kind of an odd sense of depth, which makes it difficult to judge where you are actually standing on the map. As a result, I ended up dying mostly because I wasn't immediately sure specifically where I was positioned. If I were you, I would position the camera a little higher up so you're looking more down on the arena; I think getting more of a bird eye view would make it easier to track the character in relation to the environment.
Anyway, just a minor observation :) overall, really cool game.