I had fun with it. You're UI works really well; even in full screen I could see all I wanted to from the corner of my eyes. This is something I think more action game UI's should try to achieve.
EDIT: You updated the game right after I played it. Ill update this comment later.
The game's getting better! I have no idea what button allows for the one time upgrade purchasing, but having a reason to blow up the astroids is nice. Aside from that, being able to shoot more often makes the game a faster paced and thus more exciting experience.