In the past there have been a lot of game series where having a save file in [Game 1] unlocks bonus content in [Game 2] like bonus items, unlockables etc.
But what about the opposite? Where having a save file in [Game 2] unlocks something in [Game 1]? I’ve always thought it would be neat way to implement flashback sequences or time travel in story based games. Such a mechanic ,though interesting, would probably piss some people off. But it’s something I’d imagine an eccentric game director like Hideo Kojima or Yoko Taro would do.
I think Hitman 2 has new equipment added with the release of Hitman 3, but I don’t remember if it was dependent on Hitman 3 progress to unlock.
The Witcher 2 and 3. If you get a tattoo in 2, it’s still on Geralt in 3.