Might be a pretty obvious answer but I think I'd have to say
Manhunt.
I never played the whole game, and I haven't played it since, like, 2004, but the little of it I did play has stuck with me, especially the first kill.
The game has a tiered kill system. The longer you hold the button down the more brutal the kill will be and the more points or whatever you'll get. The first kill is a freebie to teach you this system and the weapon is a
plastic bag. I honestly think that one kill has stuck with me more than any other kill in any other game. It put a really bad taste in my mouth and is probably why I never stuck with the game for very long.
Plenty of games I've played are plenty violent, and even more constantly violent than Manhunt, but usually it's tempered in some way. Like Halo, where the violence is abstracted by it being aliens you kill, or Resident Evil, where the violence is fantastical in nature. Dishonored has dismemberment, but only if you choose to do it, GTA has senseless violence, but only if you engage in it, and fighting games are usually framed as voluntary contests to some degree.
Manhunt, on the other hand, just felt
mean. It was violence for the sake of the violence. I don't mean it 'glorified' violence because I truly believe it does the exact ****ing opposite. I mean that the game doesn't approach violence as something fun or something cathartic or something exciting. I also don't think it presents its violence in moral terms, making some kind of statement about violence and our relationship with it, like Spec Ops: The Line did. It's just violence for the sake of violence. The only thing it seems to want to deliver is acts of brutality for no other reason than that they are brutal.
And that makes it feel worse to me. It's not there to make me feel powerful, it's not there to make me feel vulnerable, it's not there to thrill me, or entertain me, or teach me a lesson about myself, society, or the media I experience. It's there to let me wrap a plastic bag around a man's head and punch his skull to mince as he asphyxiates.
And I don't want to do that
