If you're into puzzles, the Rusty Lakes series is very story heavy and fun to play, while quite challenging. I imagine it'd be cool to watch and follow the story along. There is a bit of a horror/thriller aspect to it but it's not really realistically gory as far as I remember.

I think Spiritfarer might be interesting to watch too, though might get a bit repetitive.

Also a not recommended game: I watched my partner replay high on life so many times I can almost quote the entire game. It's annoying, it's just a very flipping annoying game unless you're the one playing it, and even then.