There could be more interesting things to add like some hazards such as TNT or a hard rock that bites your time. Or maybe some enemies that may chase you for a small time.
Currently the stone is a hazard which sounds like your rock that bites your time? I was in the thinking of making a lava mechanic where the player gets heat from it and if their heat gets too high they lose but it felt like too much for the player to keep track of.
Oh sorry, I actually never noticed that at first but yea I see it takes up more energy when you mine through it. Definitely better to keep the game simpler, probably it's just me feeling like there needs to be slightly more pressure to the game.
