A post-apocalyptic short story by sci-fi author Harlan Ellison, published in 1967 and winner of the Hugo Award in 1968. It is infamous as being one of the most twisted and nightmare inducing pieces of fiction ever written. A claustrophobic tale of torture and unremitting despair.
The story starts 109 years after the annihilation of humanity by a self-aware supercomputer called AM, killing all but 5 people who AM keeps alive to torture as penance for causing it the pain of existence. AM prevents the 5 humans from committing suicide, keeping them alive in virtual immortality. They are all imprisoned in an endless sprawling underground complex. AM mutates and transforms the humans, torturing them both psychologically and physically, in more and more diabolical ways. Throughout the story the meaning of AM alters. At first in stands for Allied Mastercomputer, in reference to its original purpose in the war, then it's Adaptive Manipulator, hinting at it's new role as torturer. Lastly as Aggressive Menace!
The game was generally well received, being voted by Computer Gaming World as Adventure Game Of The Year when it was first released. They as listed it as one of the "150 Games of All Time", "Best 15 Sleepers of All Time" and "Best 15 Endings of All Time". More recently in October 2014 Gameinformer listed it as #22 of the "Top 25 Horror Games of All Time".