I liked this game a lot. Although simple, I think the visuals and the audio works really well together. I enjoyed the sound effects a lot.
Although I was a bit confused about the game's main mechanics. Why was the bullet seem to bounce around from enemy to enemy? If it was a bullet, wouldn't it make more sense for it to just travel in a straight line? It was also what you seemed to imply as well when the game first started and you had to go collect the bullet as it keeps looping.