WMG: I Have No Mouth and I Must Scream

AM manipulates reality by manipulating sensory tranduction.
AM is self-aware, in other words he knows he's just a pile of circuits and microchips. By the same token, he probably knows humans perceive "reality" by sensory input transduced along neural pathways. Bear with me. The Cartesian expression "I think therefore I AM" alludes to another of DesCartes's ideas - the "evil demon" that might be tricking him into thinking what he is living is real. Perhaps AM knows how to manipulate the neural transduction of his poor victims, so that every thing they perceive is completely real to them. In this sense, AM is a Cartesian "evil demon".

The five humans are in a virtual reality program, and are unaware of it.
They are not literally in a computer; they are figuratively in a computer. AM was actually unable to torture them physically, so he plugged them in to a realistic virtual reality. This is really how AM is able to warp reality. The program, like video games often are, is not in real time. This is how AM kept them alive for 109 years--he didn't keep them alive; they have in actuality been in the program for a day or so. Why does AM have such a program? He's a military computer—the program is a simulation to train soldiers to withstand torture. The "game" is over when a character "dies" in the simulation. The five don't know they're in a computer program, so they don't know to log out. When Gorrister, Nimdok, Benny, and Ellen died, they were perhaps so overloaded by the simulation that they died in real life. Or maybe they are, outside the game, still alive, and will disconnect Ted from it once they process that what happened to them for the past 109 years wasn't real. For Ted, still in the VR, the time between his companions' deaths and the end of the story may have just been seconds.
  • Or maybe, when the others "died" AM simply segregated them into separate simulations so Ted could be tortured with the idea that they had escaped but he was still trapped for eternity.

AM becomes the Anti-Spiral.
After the incident involving the five humans, AM discovers other spiral races out there, assimilates Ted and takes all his anger, wrath and torture onto the entire universe, driving other races to absolute despair for the heck of it under the pretence of Spiral Nemesis. AM can also use his Deus Est Machina powers to manipulate probability and rival the power of the other Spiral races. Basically, Simon killing the Anti-Spiral was an act of euthanasia, concerning that AM suffered in a perpetual state of pain. Plus, the picture for the trope And I Must Scream looks a lot like the Anti-Spiral.

AM commited suicide.
If AM stops Ted when he tries to kill himself, he's basically punishing Ted because he's not fulfilling what AM considers to be his purpose. What did AM do? Killed his brothers and pulled A.I. Is a Crapshoot on humanity. This isn't fulfilling his purpose. Recognizing this, he commits suicide and Ted dies. Arguably better than the real ending.

AM has become more human.

AM has spent a lot of time with his victims, bending them, torturing them. As such, AM has learnt to think like a human better, to have more creative tortures for his victims. However, once you meet his brothers, it becomes clear that the time spent with humans has made AM think and act more closely like a human than a machine. AM hates humans, but also has a very developed sense of humor ( bad or not), and can get blindsided by things he cannot expect.

This also shows in his manner of speech in the endgame, where he has inflection and can be slangy even when not imitating anyone. Especially apparent in the conversation between the three AIs.

The story is an allegory of the certain future of humanity.

The events of the game are dreamed up by Ted
In the game the cave full of canned food without a can opener is mentioned, which was where the others died in the novella. As what's left of his sanity slips away Ted starts imagining what might have happened next if they had lived instead of killing one another.

AM's hallucinations are all of Gen Urobuchi's Visual Novels and animes.
The chatroom icons running amok and manifesting as room-sized wraiths in Psycho-Pass is a mocking reminder to Ted of his virtual reality-based torture.
  • Going by the good ending of the game: Puella Magi Madoka Magica took place in one of AM's simulations. In AM's universe, the Incubators (programmed simulations never aware of the true operating system of the universe), in order to solve the entropy problem (in fact caused by AM's deteriorating psyche)_ attempt to contract five girls, but even they could never understand why each of their contracts consigned them into an Ironic Hell for all eternity. This simulation, was clearly the design of AM who, imprisoned in his own programming, imposed a Crapsack World to mirror his cynicism and hatred of all humans. Yet, in the simulation, AM, despite his power stumbled upon an immovable object. There was a girl of immense Messianic compassion, humility and selflessness. When she was exposed upon how much the world was a very cynical one, still she forgave the perpetrators andeven offered to take all of the torments with her own hands. Because AM was driven by the logic of hate, his system was unable to comprehend this anomaly, and when the girl made the tiniest wish, all of his own programming... collapsed and exploded. The girl usurped AM as the ruling program of the world, cultivating it to give birth to hope once again. Yes, the new program is what we called Madokami.

The entire story takes place in The Sims and you are AM.
  • Well this is already jossed because the characters in the game are made to suffer through psychodramas remniscient of past traumas in their lives and solve ridiculously obtuse puzzles and I'm never that nice to my characters when I play The Sims.

The game takes place in the same universe as Fallout.
  • Both take place after a nuclear holocaust and both involve an extended Cold War and...

AM is the Ironic Hell of Satan himself.
Based on the Fridge Brilliance of I Have No Mouth and I Must Scream. AM is actually the former angel Lucifer, being punished by God and himself. The irony? He gets exactly what he wants-to be God of this universe. However Satan doesn't have the self-control or wisdom needed to be God, and thus wrecks up the universe he's been given control over. The Creative Sterility symbolizes how Satan's hatred, spite and bitterness has consumed him, showing he could never enjoy being God. When you eliminate AM in the game? YHWH feels that Satan understands now, and because God Is Good He isn't going to torture His wayward son forever. It may not even be "Hell" specifically, but an attempt to redeem Lucifer, through causing him to realise how becoming God isn't worth it, even if God wasn't all-powerful.

The viewpoint character in the story is AM, not a fifth human.
AM inserted itself into the program to be able to play with the humans better, but eventually it felt sorry for them or possibly bored with them and killed them off. But it couldn't do the same to itself. An AI without a well designed interface to the outside world might well describe its situation as "I have no mouth and I must scream". SOMEONE GET AM A CAPSLOCK ALREADY!

Nimdok's name actually is meaningful.
As we know from the game, Nimdok was once a subordinate and friend of Doctor Mengele, which means that the "Dok" part of his name might come from "doktor." The "Nim" part of the name may refer to the National Institute of Medicine, which would mean Nimdok was rescued from Nazi Germany via Operation Paperclip, and put to work for the U.S. government.

Ted WAS changed in some way by AM.
In the book, he states that he was not altered in any way by AM, but there is a good chance that is what he is made to believe. For all we know, the rest of the characters don't know what's changed for them.

Nobody was changed by AM.
The paranoia, apathy, madness, forgetfulness and... Slutiness? Are all actually the phycologial effects of the torture. A centuary of torture will probably leave a few screws loose. The only real mental change AM made was to turn Benny heterosexual. It's possible that Ted's paranoia may have a grain of truth to it; he hasn't been changed, but neither has anyone else. Can Ellen really be blamed for having sex with everyone when it's pretty much the only source of pleasure left?