All spoilers are UNMARKED per wiki policy. Read at your own risk! You Have Been Warned.
- The atmosphere. Some of the inspirations for both of the games were Portal, Resident Evil, and Dead Space, and it shows. The whole facility in both games feels so isolated and cut off from the outside world, to the point where you might wonder if something happened outside. It doesn't really help that the layout is claustrophobia-inducing thanks to the fact that there's no way to see the outside world. Special mention goes to the first game, due to the fact that most of the rooms are shrouded in Ominous Fog, the design is minimalist, and without the music, you're walking around through complete and utter silence.
- Some of the ways the enemies ambush you definitely counts as this.
- The mystery behind the facilities. Who made this facilities? What are the reasons for its constructions? What did they do inside here? All this questions are either left unanswered or ambiguously put. Nonetheless, the facilities Haydee is trapped is certainly a terrifying place to be in, regardless of the reasons of the construction of it.
Haydee
- The Black Zone is this, thanks to the creepy and unsettling music, the place being pitch-black at first, forcing you to use your night visor (which has such an incredibly limited view distance to the point where you can't even see what could come after you), the constant and surprising ambushes from the robots. There's one area where you end up finding a massive pile of dead Haydees, and another pile that seems to be in some kind of incinerator. The room itself is called D_Oven.edith in the game files.
- The game's endings, each of them ends with the player dying in one way or another only for the cycle to start anew:
- "Escape" ending: The player's Haydee attempts to take the escape route within the Blue Zone, only for nothing to happen after using the orange keycard (other than the fact that if you look behind you, you'll notice that the door became locked when you used the keycard so you can't go back), the screen then cuts to black with a similar boot sequence from the start of the game stating the player's Haydee failed their master acquisition protocols. The dead Haydees next to the locked gate also met a similar fate.
- "Master" and "Backup" endings: After fighting through the final gauntlet of Slashers in the Black Zone's locked orange keycard door, the player is greeted with an ominous sight of a hallway full of Slashers and Walkers, except they are no longer hostile and look at awe of the player's Haydee. In the final room, there's a pile of dead Haydee bodies, yet there's one still alive and standing in the middle of the pile — the Master Haydee. The former ends with the player Haydee killing the Master Haydee only to become the next one, while the latter ends with the player Haydee killing the Master Haydee along with herself, but a backup dump of the protocols was used to ensure the cycle is never broken.
Haydee 2
- The Creepers, in terms of looks, are completely different from the Walkers from the first game. Their designs lean heavily on the Uncanny Valley considering that they don't have any eyes to speak of, they look more humanoid than anything, and have pale and molded-looking skin. It gets even worse when you find out that said enemies are actually the employees that work in the very place you're trying to escape from but are affected by the entropy released after an explosion that damages Anchor at the very beginning of the game. Although, one could see this as Laser-Guided Karma considering what the company did.
- Just the fact that the other seemingly deactivated girls you find in the facility were actually real people that were kidnapped and turned into sex dolls/cyborg slashies by Jurani, and you're one of them.
