9. Blinking - SCP Containment Breach
The history of SCPs (“Special Containment Procedures”) is so vast it could probably do with its own documentary on collaborative internet effort. In short, SCPs are various supernatural beings created by forum users that were collated into a massive website and then eventually became the focus of many indie horror titles. The most renowned of all of these is SCP Containment Breach.
Developed by Finnish school student Joonas Rikkonen, the game sees the player attempting to escape an underground facility that is swarming with terrifying nasties. The primary antagonist is SCP-173 that acts essentially like the Weeping Angels from Doctor Who. If you can’t see it, it can move and if it grabs then it’s game over.
In order to stop players from staring at the creature and backing away slowly, Rikkonen added a simple and very realistic feature: blinking. The player has a certain amount of time before they are forced to close their eyes, meaning managing your avatar’s simple but very important need to blink can be a real concern.
For all of the realism strived for in modern game titles, SCP Containment Breach might be the only game where your character needs to blink. How novel! Of course it's used to cause all kinds of anxiety and potential misery because horror game developers are cruel.