The style, mood, and geometric vibes are on point. Audio and music are also a big win. Some small points of feedback:
1. There was a UI hint that said "press Q" and that simply reset the player position to the last checkpoint. That's fine, but not at all what I expected. There was a strange ghosted enemy cannon that made it seem like pressing Q would toggle that ghosted cannon to come to life in some way. Long story short: The reset button can be [Q] but try not to pair it with a confusing and unrelated graphic :/
2. I gave up on the game before acquiring circle switching mode (It wasn't clear that the game was leading me towards that mechanic). I went back to play again and get further after reading some comments though. Consider introducing the core fun of swapping shapes SOONER. What value is there in stringing players along without that mechanic beyond the first couple intro moments?
Ok, all criticism aside, this is exceptionally well made! Congrats on this game because it feels quite complete and rich with personality.