I enjoyed this game, it's simple, neat and plenty of room to flesh out a story, levels, upgrades etc. I am also happy with my best score, you tell me did I do well?
Oh another thing, I get the feeling the 3 asteroids start in the same place each time? So the player can predict this and find it fairly easy, having them spawn randomly maybe on one axis only and keep them spaced out more consistently on the other?