I got a lot of feedback about the controls in the game. I updated them to use J/K as an alternative to Z/X as well as allowing WASD as an alternative to arrows. Hopefully this fixes problems for those with non-QWERTY keyboards (or just a different preference!).

Additionally I added a gun that changes gameplay somewhat dramatically, the Crate Gun! Shoot empty crates around, block enemy paths, block your own path, completely break the game! It's all up to you!