Love the concept! I think there's a few kinks to iron out, though. There's a really easy dominant strategy: just pick one asteroid in front of you, get a tiny bit of momentum and just wait until you reach the end. It's boring, and there's not much stopping you from doing it. Maybe a timer would help with that?
I could see this being really fun though with levels to beat or a score/time attack mode. Work on this, this definitely has potential!