Problems:
1) Bullets are too slow. Hitting enemies is a matter of luck, not skill
2) Buttons in the shop menu don't look like buttons, so at first one doesn't know where to click to buy things
3) Graphics is.. well... ugly
Achievements are too difficult and game is somewhat boring after the first few minutes. Needs more *different* enemies and different arena or game modes. Anyway I kinda enjoyed it. 3/5