"AM" is an omnipotent computer, acting like a mad god. In the back story of No Mouth, three superpowers (China, Russia and USA) have created enormous computers to wage a war that has become too complex for human brains. The computers expand so much that they become united into a supercomputer that calls itself AM. It starts the final war and wipes the human race off the planet, except for five humans, four man and a woman. As the game begins, these humans have been in the bowels of this nightmare for 109 years, and of course the permanent tortures have affected their personalities. The player can select each of the characters, and must guide each character through the nightmare that AM has concocted for each of them.
The Dreamers Guild was chosen to implement the game. The company was chosen because it was considered to be one of the few developers with sufficient in-house talent to create a product of the caliber of No Mouth, and its SAGA game engine was seen as an ideal user interface for the player to interact with the environment and to converse with the characters in "AM's" world.
Though considered as "ideal," the user interface was less advanced than Dark Seed's interface. Dark Seed has a cyclable multiple-icon cursor: by right-clicking the player can cycle through the available options (e.g. look or touch). It is context-sensitive as well. For instance, when the pointer is moved over a door opening, the cycle includes an exit icon. The No Mouth interface uses an interface with verb buttons (walk to, take etc.), a type of interface that was in fact not more than a stylized version of the interface that was already used in Maniac Mansion.
The packaging of the game was again beautifully designed. Director of Sales and Marketing Andrew Balzer commissioned Bright and Associates, the company that had done the packaging of Dark Seed. The box showcases a mousepad imprinted with a 3-D image of Ellison's face entangled in a web of computer circuitry. This time extra efforts were also made for the manual, as it became a booklet with a hard cover and colored pages. Cyberdreams released a demo on CD-ROM, called "Pirate demo."
The official strategy guide was written by Mel Odom and includes a preface written by Harlan Ellison, called "Apologia for Temptation" (dated October 11, 1995). Ellison also wrote the five character biographies. The guide concludes with a long interview with Ellison about No Mouth by J. Michael Straczynski (creator and producer of Babylon 5). A video interview with Harlan Ellison about the upcoming No Mouth game was included on Interactive Entertainment CD magazine (1995, number 13).
No Mouth received Computer Gaming World's prestigious Premier Award for "Best Adventure Game of the Year" in 1996 and CGW also named No Mouth to their "150 Best Games of All Time" list. It also won the Digital Hollywood Award in 1996 in the category "Digital Darkness." In 1997 it won the Spotlight Award (from the Computer Game Developers Conference and the Computer Game Developers Association) for the "Best Conversion from Linear Media." The award was given at the Spotlight Award Ceremony during the Computer Game Developers' Conference on Monday, April 28, at the Santa Clara Convention Center in Santa Clara, CA. Dave Mullich accepted the award, which was up against games based on the Alien Trilogy, the Die Hard Trilogy, Arthur C. Clarke's Rama, and R.L. Stines "Goosebumps" series.
Dark Seed 2 was published shortly after No Mouth, in December 1995. The game had been taken into production since the last quarter of 1993. As David Mullich liked the artwork of Dark Seed, but thought there was no story to it, he decided to concentrate on the story for the sequel and looked for a writer with experience in the horror genre. He called Chaosium (H.P. Lovecraft, Call of Cthulhu role playing game line), which led him to MicroProse.