Great game, but a few things I would have liked...
First of all I really enjoyed this game and I played it for quite a while. The gameplay was fun, the animation was smooth, the music was ok, but got very repetitive for a game emphasizing multiple plays and achievements.
I think it would have also helped if there was some kind of indicator to show where powerups are. Many times while playing I found myself finding a triple shot only to disappear before I could get to it.
The achievements and badges were pretty good and fit very well into this game. The only achievements I didn't really like were the die by a certain enemy ones. So, you want me to play to some of the higher levels to encounter certain enemies....and then die? But I wanna get a new highscore?
Overall though fun and addictive.