Nice job! The art was great. I think the melee was a little unreliable; it was hard to tell if we were in range. A lot of time I would just slam into the enemy and click my mouse hoping they'd drop a health pack. Cute style, good music, and an interesting idea. Well done!
EDIT: As pointed out, I think the camera was a little close. Maybe just letting us zoom in/out would help a bunch!