Great game, the only suggestions I could give would be to make some of the areas a bit more open in the future (later on it can get hard to dodge all the bullets because it's confined) and possibly make ammo go back to where it was when you respawn. I found these two things to be a bit annoying, but I really loved the game and hope to see more!
Edit: by 'ammo going back to where it was' I mean resetting ammo count to where it was when you were where you respawn at.