If I had a nickel for every mining game in this jam I'd have two nickels, which isn't a lot but it's weird it happened twice. Well actually I guess not that weird but ya know.
There's something to be said for simple relaxing games,and this one kinda fits the bill. I say kinda because it feels a bit too grindy for me to find it relaxing. I also found it tedious rapidly press the move key, especially when I'm deep in the asteroid, I would really recommend adding the ability to hold down a move key.
The mining minigame is simple, but it works. Though I wish failing one key press locks you out of the rest.
The upgrades also didn't seem to impact my gameplay all that much, they felt a little too incremental.
I agree with the other comments about adding more variety in ore or maybe some hazards to shake up the gameplay. I guess it really depends on which way you wanna go with the game. Do you want it to be more chill or do you want the player to be thinking "oh god am I gonna make it back to entrance alive?"
For more positives, I like the visuals, the glowing ore really stands out. The blocks fit together really well, I never noticed a single seam in the geometry!
The audio was decent, music was nice, and I liked the little help screen in the main menu.
Overall, I think this was a well-done entry, great work!