[BlueTemplar]

That's still game, not metagame : burner miners are bad because polluting, that's just game knowledge, you would have trouble if you tried to do that yourself in your own Death World game.

But great point, co-op might require modifying your tactics to better work with teammates - in case of Factorio I know that you have to be WAY more careful to not make spaghetti in MP, which might also depend on the familiarity between the players - so I would say that you can potentially have a metagame as soon as you have MP, even without PvP.

But now that I think of it, you can potentially have a metagame even when playing against AI. It's just that it needs to be advanced enough to be able to play rock/paper/scissors and remember previous games against you. AFAIK these games exist, but because it's much less effort and better reward to support basic AI + MP, they tend to be vanishingly rare, especially for more complex games.