Nice game and a good idea, but the asteroids were very sparse. I managed to consume a reasonable amount of asteroids, but it felt like it was going to take too long to get to the sun.
It's a jam, so you can't expect anything to be perfect and you've already pointed out that you haven't implemented the difficulty levels, so I can't really complain :-)
The graphics are really nice and I'd like to see a more complete version.
Great job.