This game is very reminiscent of some flash games from back in the day! I think a couple of things could be improved to really help this really shine.
My main issue was the size of the map. On some runs I would run from one end of the map to the other until my time ran out and I wouldn't see a baddy. Perhaps some indication of where they are, a wider angle camera, or a smaller map could help with this.
There was also very little feedback when you get one of the baddys. Some sound effect, screen shake, or other effect might go a long way. The baddys crumbling into little particles was a very nice touch though!
I think with a bit more polish this could be very fun!