Nice! So much potential!
- I think the ball looks to round compared to the overall pixel design. You almost can't see that it rotates.
- field of view could be wider to see more of the sides of the 3D blocks
- Pause should show an - pause - overlay
- Pause on fullscreen (chrome mac) does'nt pause, but closes fullscreen
- How about some statistics? Number of shots, money gained money spent, farthest shot, deepest shot (also markers on the map for those), ...
- I'd like to have a way to reset the game in order to try more efficient ways to level up in the beginning
- Shooting upwards to gain more speed doesn't make much of a difference concerning the money you get, compared to shooting straight forward
- Procedual generation is nice, but what if I wanted to bomb my way down a previously made shaft?
- Maybe show names and price of ores in the calculating screen when hovering over those
I hope this is some inspiration for your developement journey! :)