I just gave it a go a week or two ago and it’s been so fun. Caves are basically infinitely deep, and the cave gen produces a lot of cool things. We just found a MASSIVE opening in a cave, we’ve been exploring a single room for hours and still haven’t found it all, we’re probably going to build a base in the cave cuz it takes 15 minutes just to get down there. Not everything feels finished, like the mobs are way less interesting, and the surface is generally less dense, but some things like mining are just so much cooler.