huh? I thought ur GUI so far, or at least the little "X" and "arrows" button u have are great. Kinda funny. looks like you've put some complicated mathemathical equations in there, and then you're having a hard time making the UI?
My point is: The game so far is very simple, yet amazing. I wish I would have had the idea... and I'm sure you'll do good on the UI as well.
Keep it up! I'd really like to see different planet sizes (and different gravities)...
good job, very nice idea,

Micha