Interesting and creative game! I had a hard time getting a hang of the controls, it would have been nice if the in game “tutorial” instructions were able to be read without pressing exit. Similar to that, it seems you added a custom fullscreen button, but it was only able to be clicked on the title screen, and not after that (you might still be able to change that in the itch page settings).
At first I didn’t understand that I could only select a planet in range of mine when choosing an some upgrades. Maybe an error sound or something could have been played when clicking a planet that wasn’t in range. Or maybe at the top of the map screen there could have been a prompt saying “choose a nearby planet to mine on” or similar.
The artstyle used for the starting planet was very nice to look at! Nice use of shaders!
Good job overall!