Thank you! We were really happy with the sparkling stars, because we didn't actually use any animations! It's a static, scrolling image, and I guess because of how Godot handles really small images, they end up sparkling!
There is a "stabilise orbit" button (R), but it doesn't work 100% of the time. If you're like 80% of the way to a stable orbit it'll do the rest of the 20%, but I agree that the planets lose influence a little more quickly than I'd like. After ratings I'd probably want to add more planets (maybe 4 or 5) and make the play area a little denser, so that you're closer to a planet at any given point. Thanks for playing!