I completed the game. The audio is rudimentary but it's not bad, the shooting sound and the sound when you get hit both feel right and I think this second one goes a long way in making the game feel better.
Overall I loved the game, this is the kind of game why we're here and I like all the things as bullets. Sloth is hilarious, it makes me change my judgement of the theme implementation from meh it's just narrative to hey it's cool.
Movement did not feel perfectly smooth, and reading your comment below it indeed wasn't. Also I wonder if this game could not have been a tiny bit harder actually, I never died so I don't know if you restart at the current boss or at the very beginning in which case it's fine.
That's a very cool entry, thanks for sharing.