"I think one thing that can make a game scary is a vanishing enemy. You're walking down a corridor, something pops up. "eep"! But then it goes away. You know it's watching you, The AI knows you're there and you don't have a clue if it's following you or if it's going to do the same thing around the corner." -Tylersill

"Blood, don't forget the blood all over the place. Even at the age of 66 (yes that's right) I still have an innate and abiding fear of evisceration. I think the fear is caused by an archaic suppressed memory (a Freudian term) of some event in my childhood. I thought I liked Silent Hill Restless Dreams but this game puts that one in the shade. I spent nearly $100 on BioShock and a strategy guide and I have to say it was worth every penny. Thank God I have an ample supply of Nitro pills (just kidding)." -George Robinson

"You forgot some really big ones. First off, AI. FEAR is absolutely frightening because your enemies are actually intelligent and adapt to you. No matter how good you are, if your enemies are learning how you do things, it's not normal. Secondly, the enemies themselves. BioShock has the huge Big Daddies. No one wants to fight them, they're huge... And don't forget ambushes. No one wants to turn a corner, and see nothing, turn their head and have a dozen enemies with guns attacking them. Thirdly, level design. If you're in some small room, and you hear enemies outside, you better hope you have a spare grenade. And just extra little things like blood on the walls, or dripping water. Pictures, objects, just level decorators add to the horror of the game..." -Tyler Kirkham

"In my humble opinion you are forgetting something that makes a good horror story either for a Game, a Movie or a Book (ok I know you are mostly referring to videogames, but it is shown in good games). Contrast... They show you the normal and placid world around you (or maybe not so placid if we remember Doom 3 or The Suffering) before throwing hell into the world. Sometimes is maddening to watch the normal world as it dissolves around the character's eyes (and yours) and once into that there is no coming back..." -Montalve