Usually I suck at first-person shooters, but I got the hang of this game pretty quick. The FPS mechanic is a nice addition, but not really critical to the game. I liked that the bullet count and reload timer persist even when you leave FPS mode and come back - no glitch to exploit there. Excellent job :)
Bug report: I managed to make the "enemy count" go into negative numbers. I suspect I was killing them before they crossed some invisible boundary which counts them as active.
Suggestion: In FPS mode it would be nice if we could reload before we run out of bullets.