It works. You mention adding more to the game, right? While it certainly works well enough, it needs a LOT more to be a solid game. For one, you can shoot as fast as you want without reloading. This leaves me to wanna just throw on an auto-clicker and wreck face... which isn't really challenging at all. Maybe make the player have to aim and make their shots count before they must reload or something? More weapons would be nice, too. Enemy variation is a MUST. Make some that stay at a certain distance and shoot back or smaller ones that zig zag or big ones that take many hits or one that splits into several small ones or that leave a temporary hazard. Get crazy! Music, sound and certainly some more art assets would be great.

Anyways, it works! But... that's just it. It works and that's about it. ^^; Add on it, though! You could make something nice. :P