Yeah, just what the title says: What in a game do you actually consider scary, or make you jump, etc.
Me personally, is probably dark areas, no weapon and there’s obviously something trying to kill you.
What are some of yours?
Something that is chasing me… in half life 2 episode 2 when the antlion king chases you in the caves i had to pause the game because my dad was knocking on my door to ask me why i was screaming like a girl.
Sounds coming from areas that you can’t see (such as around corners or behind doors). Things that happen suddenly. Things that change when you aren’t looking.
Nightmare House 2 does a lot of these. It was epic. 
- Things chasing me
- Unknown noises
- Unknown whereabouts of enemy
- Well done “pop-ups”
- The creation of the monsters in the game not being explained
This is how Amnesia got me.
Moments when you aren’t quite in full control (if the character’s injured, or going slow for any other reason), and stuff that you aren’t sure is real (normally in visions or when your character’s losing it, such as FEAR or Call of Cthulhu).
Some subtle creepy things you see or hear occasionally in a dark an eerie setting where you’re all alone. I find suspense far more disturbing than actual monsters. Bonus points if you never really find out what the hell is happening.
The fact, that there are enemies, and you can’t protect yourself or attack them (like in Amnesia).
Who tried Afraid of Monster: Director’s cut?
That’s some real scary shit.
It’s mainly the music and sounds, like in amnesia there are always sounds everywhere that just aren’t explainable and the music makes you really tense. also, when being chased by a monster you hear a noise that keeps getting louder when the monster that’s chasing you gets closer. It just makes you freak out A LOT. Try playing it without sounds and you won’t be scared 
I’d have to say the same thing that Corrupt said, strange noises. The actual “scariness” is that you’re making up every possible horrifying thing that could be making those noises. I feel as though video games tend to take away this fear by revealing a monster/enemy that is not at all what you’re picturing, i.e. Dead Space. What really makes me tense is when there is a lack of music. Silence I find is key to making a more scary and almost realistic environment.
A game wherein the creatures that stalk you hide in the shadows for an indefinate amount of time. almost never showing up, even tho you know what they are and that you dont stand a chance if they do descide to attack. its not a matter of if but when. and if the game makes them attack at diffrent times throughout a second playthrough that makes things all the better…
Also i like the conscept of “Objects in mirror are closer then they appear.” Where you see a creature far away when looking in a reflective surface only to turn arround and have it breathing in your face.
Really good Music/sound ambiance in a game makes it scary or not. Unless you’re a little kid, then everything is scary.
I have never been “scared” by a game, but I have been creeped out and put on edge. The atmosphere of the STALKER games is a great example; the combination of mutants and natural phenomenon provide for a very creepy environment. Also, the fact that there is some type of scientific explanation included in STALKER helps one suspend their disbelief and accept that whats going on, “could” happen.
atmosphere, lack of action, slow paced, depending on something/someone else (dead space 2 would have been awesome if you played from someone elses perspective, especially the ending when [COLOR=‘Black’]the reactor starts to melt and you have to escape somehow, if you survived that is.) and silence.
play dead space…take everything from that, and you have a shit scary game :L
Noises for one, and helplessness, for example in deadspace 2, there are the necromorphs after you, but you have your gun and can kill them and you’ve other people that your in contact with, but in Amnesia, you’ve nothing to defend yourself with, and on top of that, you’re alone (I think haven’t beaten it yet) so that adds to the feeling that its just you, so any other noise you hear, you mind makes out to be some horrific monster.
Scary atmosphere + intelligent AI = HOLY SHIT
Condemned is a good example of this. You’ll see someone run behind a ticket booth or something, but when you go to take care of him, he’s not there. You then get a sudden whack to the back of your head as you soil yourself, as he had actually doubled back around and flanked you.
Besides that, I guess sudden images or sounds.
OH and the actual REAL terror when you must face a large swath of enemies or a boss with little to no ammo.
IMO that’s just stressing, not scary.
for me, scary is slow, scary music, and you are just waiting in a dark place for something to come at you…
inconsistent lighting contrasted with consistent lighting.
Constant low ambient noise. (but usually more effective with an ear popping silence)
Enemy design. Not LOLOLOL TEETH AND SPIKES EVERWARE LOLOLOLOL. That’s not scary. Scary for me is twisting the human body into familiar shapes. Sexual or innocent. It should be something that appeals to us executed in a grotesque way. Sometimes plain mutants work too RE4 regenerator but rarely. Silent hill has nailed it imo. Not a lot of other games have come close in terms of design.
Overly complex surroundings help too. More nooks and crannies to not see something that could be there.
It’s gotta be paced right too. There’s gotta be calming moments. Hell, makes it even better because then there can be a “disguise” for another stressing moment.