So we've identified that Portals narrative is built into the experience of the player, and that this experience is guided by level progression like most other games. Before we can analyze and critique Portals narrative, we have to identify which parts of the game are analogous to common elements of literary (or even film) narratives. In Portal, the player takes control of the main character, Chell. Chell uses the portal gun to manipulate her environment to overcome challenges set by Aperture Science, a fictional facility. The purposes of these tests and Aperture Science are shrouded in mystery. The second character is GLaDOS (Genetic Lifeform and Disk Operating System). GLaDOS is not the narrator, but a character with limited omniscience. Though she informs and guides the player through an intercom system, her limited omniscience is expressed through the placement of cameras that monitor the players progress. Whenever a camera is tampered with by removing it from the wall, the player is informed by GLaDOS not to do so. If, the maintenance of the cameras was integral to maintaining gameplay, as the player proceeds to destroy the cameras, a light scolding is their only consequence. The credibility of the narrator also comes into question very early in the game. GLaDOS tells many lies throughout the game and, when caught in a lie, she casually back peddles her way out of it.
" As part of a previously mentioned required test protocol, we can no longer lie to you."
"The Enrichment Center regrets to inform you that this next test is impossible. Make no attempt to solve it."
"Fantastic! You remained resolute and resourceful in an atmosphere of extreme pessimism.
"Have I lied to you? I mean in this room. "
The primary plot in Portal consists of the main character completing a set of challenges. The subplot involves discovering the true nature of the Aperture Science facility. As it turns out, after you complete all the missions, GLaDOS tries to dispose of you through fire and flames. At this point in the game, the plot shifts from a "hero's quest" (in this case the quest for cake) to a quest for freedom. Everything that GLaDOS has told you up to this point can't be trusted. Before, the hidden passages in the walls revealing interesting personal notes from other test subjects who've gone before you, were just whimsical asides. Now "the cake is a lie" means more than a failed promise of dessert. The "cake," GLaDOS, and Aperture Science are all a lie. For the player, everything they've been experiencing and all the puzzles were just a clever ruse. The only way to break free from the lies is to seek the source, GLaDOS.
It is only fitting that the Portals narrative structure simultaneously describes it's design (gameplay) purpose. From Valve's website...
"The game is designed to change the way players approach, manipulate, and surmise the possibilities in a given environment;"
Using the Portal gun the players sense of perspective shifts from overcoming Chell's individual perspective to overcoming a perspective that encompasses GLaDOS and Aperture Science. Change the word perspective with "environment" and it's clear how the narrative parallels and reinforces the gameplay.
Now that the narrative has been defined, it can be critiqued more traditionally. These are the areas I would focus on and some of the questions I start with.