they don't have to *look* different not like they looked different in FO2. besides, most underground facilities were made by Vault-Tek, they should look similar because of unification.
they have to play different, which is what WD said, I think.
You have no right to talk until you play Shadow of the Colossus. Fo' real this time.
That said, I'm not sure what the hell you're saying. Fallout 2 didn't have dungeon crawler-type locations. And underground facilities made by Vault-Tek? What? Seriously, are you talking about the same thing as me? Most of the game dungeons were either metros or office buildings.