i love the concept of this game! i wasn't able to figure out how to upgrade anything or figure out how to get dust and ore back to the main area though, but I imagine it changes the pace of the game quite a bit! I could see a tutorial of sorts, could be incredibly short even a cut scene showing what an exit looks like/how to get into the next area / how to get back to the start. at some points I'd clear an entire cave and not know what to do next.
I imagine not being able to return with my dust/ore is my own user error and not on you whatsoever, but again, I played for about an hour and couldn't figure it out. Perhaps consider making an intro as you continue to expand this game for dummies like me? if I knew what I was looking for i'd grind it out, but I'm a stumped boy!
would recommend! Keep up the good work!