I really like the concept! The loop of mining for customization options is fun and can even get a bit addictive. The controls feel good to use. Art and various visual effects look fantastic. Music would be a nice addition, but you'll need to be careful if you want to add sound effects so as not to make them too overwhelming given the amount of blocks that are getting broken.
I think that the game would benefit from more special blocks and fewer player powers. Maxing out equipment makes the mining sessions longer but not more strategic. If the line hits and other such effects were associated with blocks instead, and the player gets very few actions, the game would be a lot more about how you place your strikes to set up big chain reactions which may feel more rewarding. It could also be good to create a bigger sense of investment in a single mining run. Perhaps hitting quotas could unlock lower levels with rare treasures?
I was already engaged enough to unlock everything, so I think that you're incredibly close to making something fantastically fun if the gameplay is refined a bit!