Wow, this is game is a whole ass vibe, nicely done!
I struggled a bit with the velocity of the player, as I'd sometimes float by a comet or moon and assume I'd nail the trajectory only to be just slightly above it. I'm sure that's intended at lower sized gameplay, but I think tuning it up slightly could help someone get into "the zone" a bit faster.
I really loved the art style and ambient direction of this game a lot. It's hard to make a minimalist game that tickles the same part of your brain that something like Mini Motorways or Alto's Adventure do, but I felt that when I played!
If you're considering polishing and releasing this, I think this could do tremendously well on mobile!