Nice litte "experience" i feel its missing an end or a goal, maybe i dont understand endelss runners. i dont like that the "mine" button use the mouse insted off a key.
I would make the game dark and darker the deeper you go and add enemies to make it like a small arcade experience where the goal is to go as deep as possible. maybe even add the bottom as a you beat the game type deal.
Art is nice, game works well did not find any bugs.