>>41202Minetest?
Is just beta minecraft with a roblox or gmod like implementation where the game is a front end client like thing and you download the game modes - campaigns and mods into it.
The world generation underground is just as massive as the overworld surface.
Im pretty sure that the guy that made it and said that he wanted to do what mojang didnt was to dial up the shit your pants paranoia that being in a cave caused and made minetest with that in mind.
Which to his Credit works out pretty well.