Half Life with ultra-realistic graphics Gen-3 video to video Runway ML Artificial intelligence - YouTube

This isn't actually running in-game, the guy says that it's only working on the output frames of the game and thus has no reference for actual geometry of the levels, but it's an interesting concept nonetheless.

I'm particularly surprised how well it handles reflections off water, because a lot of those details aren't actually present in the source(lol) material