i noticed there's some extra minerals that have no platforms to sell them at. and there seems to be no max speed for the jetpack, as it just keeps getting faster if you go straight up from the surface, and the game really doesnt like me doing that
This is true. I didn't think that people would play so long to get the better resources from the depths. The faster falling speeds can break the game a bit and I will add a speed limit in the future, but for now, I think it is a cool discovery once you have played through the rest of the game, even though it is still a bug.