I'm going to be super nitpicky because I loved it and it's my favorite game after 40 or so games, so here are my little nitipcks!
Armadillo spawning seemed unfair. Not sure if buggy, or if they are meant to spawn out of thin air. Also sometimes they would never move.
The guys with shields kind of just slow the game down, not a fan of them.
The barrels can be pushed into the top wall a tiny bit.
That's it, that's my three nit picks. You did so fantastic!