What game scared you the most?

Personally, I am afraid to play any horror game on my own. However, a game that not everyone remembers, and I am afraid of playing to this day is SCP: Containment Breach. Anyone who has played it or has minimal knowledge of this game knows how scary the ambient sounds are. The worst moment, however, is when you turn around, only to see SCP-173 standing right in front of you. When I sometimes play this game with the intention of "winning" it, usually at some point I just can't go any further, being too scared, and turn off the game in the end.