It really depends what kind of game you want to play.

If you want a fiction first game where the characters are a bunch of “freedom fighters” in an hostile environment, you could try either Spire or a|state, but you would need to heavily modify the settings. It would be a lot easier with a|state, which is a dystopian future hack of blades in the dark.

Maybe a modified twilight 2000 or Mutant Year Zero? It depends on how grim or heroic he wants the game to be.

My guess is he wants a steampunk setting with survival and base building mechanics.