Nice game : ) and the alien encounters are very funny !
I'm asking myself, do you generate the planet textures procedurally ? They look so great!
I used the kenney.nl planets asset pack and layered 4 different parts files on top of each other. The I wrote a shader that simply multiplies a tint color. The scene script is set so that I can specify frames and colors, or go full dynamic within a hue range.
I really liked the art on your planets too. They had a ton of character