@starkatt I don't know of any but let us know if you get any good suggestions
...actually depending on how the world generates Dwarf Fortress might fit this?
@Felthry Dorfs is a super surprising suggestion and I'm into it :)
@Felthry the game is a bit too much for me personally (I've tried on a couple occasions) but I super appreciate what it is and have seen some quality lets plays.
@starkatt As for more accessible games, the backstory of Avernum feels a little like this (though the apocalypse in that case was an empire gaining control of the entire planet), with how Avernum is a system of caverns deep underground where the empire sends people to die--and yet instead the people came together and found a way to live down there
still, a bit distant from what you want
@starkatt oh! I have one! The minecraft mod pack Regrowth, which is focused on pretty much exactly this: restoring a dead world
@troodon @Felthry @starkatt Is the FtB launcher version the canonical one? https://ftbwiki.org/Regrowth