8. Alien
Yeah, yeah, I know. We have a plethora of games centered around the Xenomorph mythos, but hear me out. What we actually have are tons of Alien games, ones involving terrified glass cannon marines unloading clip after clip into the darkness of an infested ship/base while the beasts lunge at them. Oh yeah, and sometimes a Predator gets thrown in to the mix. Theres nothing wrong with that set-up except they dont really capture what Alien (as in Ridley Scotts claustrophobic masterpiece, not Camerons classic action film) is about: being stalked by a predator much more powerful than you are and having no means to fight it. Sure, playing as the marine in Alien vs. Predator is a scary experience, but you still have a gun! You can fight back. You dont necessarily have to use your wits if youre good at strafing. A game where you have no means of fighting a single xenomorph would be terrifying.
How to do it: Shamelessly rip off Amnesia: The Dark Descent. Amnesia is a game that has the player solving physics-based puzzles beneath a creepy Prussian castle while being pursued by monsters that cannot be fought or killed. The player can barricade doors or hide to temporarily escape the beasts, but there is no way to kill them. Amnesia takes what works in the survival horror genrenamely, instilling an overwhelming sense of helplessness in the playerand focuses on those aspects while getting rid of several of the genres flaws (e.g., unwieldy control scheme). Now just think about that same game except have it set on the Nostromo or a ship like it with a single xenomorph stalking you as you try to save whats left of your crew and survive long enough to make it to an escape shuttle.