[1] The player, taking on the role of the unnamed astronaut protagonist, returns from a failed 100-year voyage to 61 Cygni to find the Earth devoid of humans.

Cars are rusted and covered with moss, the streets are completely barren, and everything appears as though the entire human race had just vanished suddenly.

Info gave the Commodore 64 version of Portal five stars out of five, describing it as "engrossing, fascinating, and somewhat disturbing ... like a murder mystery, an expedition, and having amnesia all rolled into one".

[2] Roy Wagner of Computer Gaming World described the story as "interesting and well-written", but felt the interface was tedious.

[4] A hardcover novel, titled Portal: A Dataspace Retrieval (1988) and composed mostly of the text from the interactive novel with some new additions, was written by the same author, Rob Swigart, and first published by St. Martin's Press.