Maybe it's just the little things
In Planescape: Torment…
You can die. You'll come back to life. This is an integral part of the game.
You can join a cult that worships death, or a cult that believes that everybody is a god. Or you can just become an anarchist.
You can visit a pregnant alley, then prevent it from getting an abortion. This makes even less sense than it sounds.
You can piss off the deity-like Lady of Pain and find yourself trapped in a maze for all of eternity.
You can kill the incarnation of your character's mortality.
Although Planescape hasn't aged super well-and you need a high-resolution mod if you plan to play it today-it's a special sort of game, and it's had a significant impact on a lot of people. No wonder so many people want to throw money at the sequel.