Portal

Portal's plot is revealed to the player via audio messages or "announcements" from GLaDOS and visual elements inside rooms found in later levels. According to The Final Hours of Portal 2, the year is established to be "somewhere in 2010"—twelve years after Aperture Science has been abandoned.

The game begins with Chell waking up from a stasis bed and hearing instructions and warnings from GLaDOS, an artificial intelligence, about upcoming tests. Chell enters into distinct chambers that introduc...