Playing this game for a while now, and I love it. I always look forward to new updates. Granted it is only in Alpha, but I some improvements that should be up for consideration along the way. This list will continue to grow as I continue to mess around with more and more.
Improvements:
-Better post-impact stuff: If a planet is hot enough to be molten, it shouldn't keep impact craters after it cools as it would be liquid.
-Thermodynamics: Any body that is hot enough should radiate heat to surrounding bodies. It would be nice to have a moon turn molten from orbiting a planet that is so hot it acts like a blast furnace.
-Automatic magnetic field generation based on ferrous composition and rotation rate.
-There shouldn't be convective cells on white dwarfs and neutron stars.
-Maybe a revamped launch system, where you can hold down the mouse button and continuously launch whatever at a specified rate. The continuous firing could be optional.
-Supernovae should obliterate everything within a certain radius, and its color scheme should be based on ratios of materials. Also, they should look different each time.
-When vapor of one body accretes around another, it should add to its mass.
Suggestions:
-Add tides to planets with water
-Add life formation.
-Plate tectonics would be cool if there was a way to implement it.
-Be able to change the atmospheric characteristics such as color, thickness, and composition.
-Spaghettification for Black Holes.
-Accretion discs
-Stellar winds/stellar storms.