Wow, this game is ground-breaking!
Jokes aside, this game is excellent. I'll admit I was initially worried the game would just be grindy or low effort, but I was very wrong. I have very little criticism to give. Super satisfying, the sprite work and sound design is stellar, and everything feels snappy and responsive. I did end up finishing the game, and the whole experience was quite fun. One thing I'd recommend is adding music, the mining could definitely benefit from it. Perhaps implementing different music for each stone type region could make you feel like you're progressing.
Either way, it was a very fun experience, and I'm sure you'll end up with a high rating. Hope you end up placing high!