I like the idea and one button gameplay, feels like it can become a good mobile game. It's fun to play, and the graphics is simple and unobtrusive.
The difficulty might be a bit high. I'd suggest you increase the movement speed gradually so the player can get used to it. Also, now there's no reason to "collect" the asteroids. I think you could change your scoring system to take time into account, or maybe add some kind of coins/health/etc that you need to circle in order to collect.
The audio had some issues (jetpack sounds stopped on the second level), and I think it'd be better to add some music.
Looks like a lot of critique, but I think it should be easy to figure out. The important thing is that you have a really good mechanic here. Great job!