I feel like the graphical presentation is just a few steps from being something amazing, as it's now it looks like a well made flash game, not that it's a bad thing, I'm just pointing it out because I feel you're on to something really cool with the style.
I didn't find the gameplay to be that fun, but I'm quite sure it could be a great game with some tweaking, though I'm not even sure if it would be better with a slower more methodical style, or as a fast twitch based shooter. As the game is now I felt that taking damage was often unavoidable.