Digging for Survival: I Become a Gold Miner

Global catastrophe + battle royale + dark creatures + mining + system + multiple female protagonists People all over the world were transported to the underworld. The endless underground world can only go down. People only have one way to mine, and they keep digging. Maybe you can dig up a treasure chest. Maybe you will dig into unknown passages. There will be mysterious creatures by your side tomorrow night. And the ground is settling every day faster than you might expect. Or be crushed into a pulp. Or dig down as hard as you can! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.