Good work
That grey sattelite (or however you do spell it) is rather hard to avoid. My technique of rapidly circling the moons at a short distance away didn't work on that one.
Good job, and probably places for loads of creative additions. Personally I'd like to see some collisions between moons, and between moons and asteroids, maybe wormholes that periodically appear and teleport you to a random screen location if you hit them...
Anyway, good game