I don't feel comfortable using an issue tracker for this project right now, because of the possibility of losing that data or it not being kept with the code, so issues are being tracked in the repo - here.

Add a test moon to verify nested orbits work.
Figure out how to integrate player movement with orbits instead of being separate modes of movement.
Figure out a concept of spheres of influence based on body mass.
Make finding a closest object BY sphere of influence so that orbits are a bit better instead of JUST distance. (Basically, it's higher mass reduces "distance" when sorting. Maybe just do distance - mass because that's a quick and dirty way to have something working. Except my mass values I think are very large, so maybe radar_size or something between is a better scaler. Although I want mass and size not directly related so it SHOULD be based on mass.)