This is begging to be made a rhythm game, great work, i love the visuals and how you don't need to use sprites to make a beautiful game.
Just as a tip, you don't need to use a bunch of circles to make the tracer of the planet, you can use the node Line2D in godot for the same result with more options, I used this video to make the tracers in our submission, with this you could do more stuff like satellites and such.
Anyways, great game!