Embrace the Darkness: In a world decimated by disease and decay, all you can rely upon is the cover of dark. Adapt, or Perish: As you traverse immense, dynamic environments, you'll have to use your wits to eke out every advantage you can get. Challenge the Inevitable: Under the direction of a cold and uncaring A.I., you'll fight to ensure that the infection never spreads to Earth, no matter the cost of life ... or the cost to your own sanity.