I was able to mine and pick up some coal. It did not give me any money though. When I died, I respawned in a different area where I could not go anywhere. I did not understand how to kill the enemies or decrease their hostility and what the "drilling rate" bar meant.
The hefty filesize is also a problem that might put people off from giving your game a go. I think there is some optimisation to be done on assets to bring the filesize down.