Nice graphics and controls, particularly when I learned how to mine upward.
I enjoyed the use of light as a single point on the player. This is about the only way to do it in 1-bit and the scale was good so I didn't lose too much screen to it.
If it was mine, the next improvement I would be add would be a 2x speed up option. Some rocks take too long, and the pace is such that impatient players might get frustrated. I loved the pace BTW.