Wow, really cool implementation of the limitation theme. The 1-dimensional movement started out as a bit of a gimmick, but you evolved in really interesting ways over the course of the game. My main recommendation is that ammo would spawn a bit faster, I ran into a few situations where I was at full health, and then ran out of ammo, and died because the pursuing enemies kept running into me before more ammo could spawn. But overall. great work!