Didn't expect to see an orbital mechanics simulator in the 64x64 jam. I think the game would look better in higher resolution, but you managed to fit it in - good job.
I liked the atmosphere and music.
Shame I couldn't figure out how to refuel your ship. I suppose it's not implemented yet.
Some knowledge of orbital mechanics helps you - for example to catch up to a planet you actually need to slow down. Otherwise you overshoot and die in space with empty fuel tanks. So, the balance - the amount of fuel given to you, is just right.