Thanks for playing the game! Definitelly on the more interesting feedback, didn't really cross our mind to test the game for color blindness. Considering the planets are based on actual solar system planets, it might be a bit difficult to adjust them to better distinguish between them but we have been considering more clear indicators, potentially a number to explictly show their size right on the planets themselves. The checkmark can be changed and definitelly wasn't something we accounted for. It's definitelly feedback we'll try to keep in mind for future projects as well.