I was very pleasantly surprised by how pretty this game is. I expected a straight up asteroids clone, but your game is so much more engaging. And pretty - the effects are simplistic, but very fitting and a lot of fun. The carrier ships (both human and alien) are absolutely gorgeous, love them.
I got confused at the start since sideways moving is very slow, almost non-existant - but got used to it quickly. Enemies are tough enough to be a bit of a challenge, but not too hard once you get used to it. Shooting powerup is a REALLY nice touch, and asteroids not damaging you is a blessing - otherwise I woouldn't have been able to complete your game.
I loved it. It's a very nice arcade action that's not coin-munchingly hard and not piss-easy. Just the right amount of challenge.
Oh, and the asteroid breaking effect is very impressive/