The visuals are so good! I really enjoyed the flashing lights and the atmosphere quite a bit. I did notice that there are some overlapping models in the elevator at one of the points when the lights are lit up, so some texture fighting is going on there lol. But I really immediately enjoyed the atmosphere. It reminded me of the caves in the mining level of banjo-tooie
I would highly recommend adding an option to change the font, it was nearly impossible for me to read.
One final note on polish, I would love to see some particle effects when mining ore, just to show the player that they are having an effect!
As far as actually playing the game goes, I think it would be really cool to make a bigger deal out of the cave ins! Making the audio a bit louder, and more directional so I can hear where the cave in is happening, as well as a small amount of screen shake would really draw my attention to it!
I also thinking making it so the player can't get stuck early on (I got trapped in the bowie room) would be nice just to avoid it being annoying. Happening later on once you are already hooked into what the game is asking of you makes it easier to go "dang, guess I'll try again".
Overall great job, especially seeing as this is your first 3D game :)