- Where to start? The Juicer machine? The cybernetically-altered human slaves with wires for eyes and exposed guts? The omnipresent protein pipes that you know are filled with ground human meat? The possessed ghosts of children doing acts of evil everywhere, including at least one little girl that kills her father on Earth? How about the ever-present screams of agony of said children and of other people? Or the ultimate fate of Tommy's girlfriend, Jen? Or how about that fucking nursery rhyme?
- The game has one part early on in the alien space ship that essentially cements the atmosphere of abject terror for the rest of the game. The fact that the ship itself is alive is a little creepy, sure, but at this point in the game action is taking over more and you're starting to get the hang of it and control your shock at the organic horrors present in the ship... until you reach a seemingly empty room at the end of a particular level. The laughter of children echoes about the room, and suddenly a horde of murderous, disturbingly innocent-looking, giggling child ghosts appear and begin to attack you, giggling and singing nursery rhymes all the while.
- Throughout the game, children are mutilated, torn apart, and slain - one of the first atrocities you'll see is a child being possessed and tearing apart and impaling their sibling, and you can find another in a corridor that runs away from you and hides in a vent... and screams as whatever was in there rips him apart. In fact, the ghosts were added at a late stage in development; previews as little as six months before the game's release showed full-fledged, flesh and blood possessed children instead of ghosts coming at the player to rip him apart.
- The fact that somehow, the Sphere aliens are able to invade the afterlife.
- Anything. Anything having to do with Art Bell describing what's happening in the US through the calls of his terrified listeners.
- For those particularly squeamish about their eyes, the alternate fire of the Hunter Rifle fits very well. Even if you know that the appendage that shoots towards your eyeball is harmless and in fact is your scope, the sight of a tentacle with three sharp prongs darting towards your eye is pretty cringe-worthy (charmingly described in the Penny Arcade comic as the gun "licking your eyeball"). The first time the player does this is an almost guaranteed Jump Scare.
Nightmare Fuel / Prey (2006)