IGN has cranked out an extensive nine-page history of survival horror video games, tracking the subgenre from 1982's Mystery House to 2008's Dead Space. As expected, Irrational Games' System Shock 2 gets several paragraphs of exposure too, starting on page six:
One of the first and most important games of the revisionist survival horror movement arrived before the genre was in crisis. In fact, System Shock 2 wasn't even considered a survival horror game at all when it was released. The clever hybrid game managed to completely avoid the usual sort of survival horror gameplay seen in so many PlayStation games, while still tapping into the same core principles that make them so scary.
System Shock 2 was not really big on labels to begin with. It looked and controlled like a first-person shooter, but it had the character growth and customization of an RPG and a developed inventory system. Underneath all these elements, there was a sense of horror and tragedy that permeated everything. Like many games before it, the story of lives ruined or ended unfolded through the logs and journals of those left behind.
The team at Irrational Games wasn't looking at Resident Evil or Alone in the Dark for guidelines, but when faced with the challenge of making a truly scary game, they came to the same conclusion. They identified two main elements, isolation and vulnerability, as being the key themes in the story and gameplay that contribute to fear. Trapped on a space station and surrounded by corpses, the player felt helplessly alone, and with minimal resources and abilities, death was always looming. Immersive and sometimes deceptive use of sound and lighting helped to reinforce the sense of dread with a strong audiovisual component.