Graphics: Very well done sprites, good color scheme and smooth animation. I like your style!
Sounds: A little repetitive, could have used some music, but the sound effects were decent. I liked how there was a different sound effect depending on what you shot.
Gameplay: Very fun and fluid. The only unrealistic parts were having infinite ammo and the fact that most of the time you weren't even looking at your own player. It was cool hiding behind stuff and all that, but the player healed a little fast, which made the game kind of easy.