Even in the opening dialogue one must exercise discipline with the spacebar!
Well, I went straight for the worms making the breathing sounds, and when I read that right click was saw, I decided to find out whether I could kill them. No, but you could send them back into their hole for a short time. Some distance attenuation on the worms would help gauge whether the player has time to continue drilling a rock or not; the fact that the entire map can hear a worm on the opposite end can make gathering vs. repositioning more confusing than I think it needs to be. Sometimes tunnels would give you directinoal cues which gave a clear indicator of the worm's ETA, but some audio focus on that area specifically could really change the atmosphere for the better and open up more opportunities.
It'd be nice to get some reward for the end of an expedition that extends beyond a single run; currently it seems every expedition exists in a vacuum and has no impact on anything that comes after. Plot progression, mech progression, or at the most basic, keeping a running tally of total income earned (and maybe adding a simple win condition like "get $50,000 to bring your family and become citizens") would all add some depth and incentive to the game loop.
The atmosphere was good in terms of both visual aesthetic and aural ambience. The worm sounds worked even if the distance attenuation was absent. I like the cockpit, it was flavorful and unobtrusive. Not sure if the levels were procedural, but this is a nice start to a bigger game, and as it is, is a technically functioning game loop - tying runs together with a running tally or something would definitely bring it home. I'd almost prefer lore progression over tech, at least to start, especially given the possible unwillingness of the mining operation to invest anything into their equipment should one of their pilots (the player) start to make headway.
Well done on a good submission. I enjoyed the darker theme, as well as the plot outlined in the game page provided. If you continue at all after the jam period, hopefully you tie more of that plot into the gameplay, as I think it would go a long way.