Really fun and satisfying game, I could play this for hours. The core theme is genius and it works fabulously. It turns mining into fun and strategic. The world is immersive and makes you want to explore it. I hope this becomes a full game and gets more stuff added.
My main criticism is that resetting the world while keeping items on death doesn't make sense to me. It mostly feels bad but doesn't have enough consequence, where it should have been the opposite. There is little incentive to commit to the world and build carts when you know a single mistake can ruin it all, even though that's one of the most fun parts of the game.
Personally I think it would work better if the world remained forever but on death you lost your money and items and teleported back to the elevator. Would incentivize you enough to avoid mines at all cost without being frustrating in an otherwise fun and calm game.