Clock Tower for SNES comes very close to this the first time you play it, but all other times it's pretty tame (unless you find the Scissorman in a spot where a vital item is normally located). Darkseed is the scariest game I've ever played. It's not violent, bloody, gory, etc., and has no serial killers or zombies. It's just so surreal and disturbing it scares the stuff out of you. And Darkseed II is worse...