Quests bug out on me a lot halting my storyline, so I get out my shovel and pickaxe and have at it. Of course there is the obligatory dig out Gerdy shuttle at the start, though I think she was not thinking multilevel dungeon.
This is the only mining game I have played that you feel like your avatar really is mining. Usually even sandbox games you just stand at a fixed node/grid and wack it until it depletes/dissapears, there is no interaction with the environment at all, no creativity possible. My current project is sculpting the ore nodes out of the limestone at the crater, with side benefit I made a huge limestone castle at Camp Carter.
The mountain at camp carter on the shore side has marble, I wish its voxel build version was more marble looking, and the limestone/rock build textures patterns would horizontally align. The organic versions before mining look perfectly organic, just the built versions are lacking.