“Before Portal, Aperture Science conducted experiments to determine whether human subjects could safely navigate dangerous “test chambers”, until the artificial intelligence GLaDOS, governing the laboratory, killed its employees. At the end of the first game the protagonist Chell destroys GLaDOS and momentarily escapes the facility, but is dragged back inside by an unseen figure later identified by writer Erik Wolpaw as the “Party Escort Bot”. A promotional comic shows estranged Aperture Science employee Doug Rattmann, who used graffiti to guide the player in Portal, placing Chell into suspended animation to save her life, until the beginning of Portal 2.” – Wikipedia Portal 2
Again, you are Chell and you wake up in a hotel room looking stasis chamber and run through a few physical and mental “tests” and fall back to sleep. You are awoken again by an automated message that cuts out and a Personality Core called Wheatly is at your door. The Aperture facilities look dilapidated and run down. They appear to be crumbling as you stand there, again literally.
With the help of Wheatly you make it through the usual test chambers until you reach GLaDOS’ chamber and wake her up. You manage to switch Wheatly for GLaDOS and Wheatly takes over the facility. You are again plunged into testing by a psychotic AI. GLaDOS gets her core personality attached to a potato battery.
You explore the abandoned areas of Aperture Science and travel through a sort of time capsule of Aperture’s HIstory, not so perfectly preserved. We get to hear pre-recorded messages from Aperture’s creator Cave Johnson., as well as Wheatly and GLaDOS the spud battery’s commentary. The dialog and pre-recorded messages take center stage in this game. The actual test chambers are neat with the additions of the propellant gel and velocity gels and the like, but they all take a backseat to the dialog. “When Life gives you lemons, get MAD! Ask to speak to Life’s manager! Burn down Life’s house… with LEMONS!”
They added a co-op mode where you and a friend can play as two companion testing robots. The games are fun and you get GLaDOS leading you through each test chamber like the original Portal game did. The robots’ cute gestures and the addition of a second portal gun makes this part of the game amazing. No real zingers from GLaDOS, but I was too busy trying to figure out these challenging puzzles to care. I keep going back to this game, even after I’ve beaten it 20+ times. It is just so much fun.
When you eventually work your way back to Wheatly, with GLaDOS-spud in tow, you battle Wheatly in a similar manner as you did GLaDOS in the first game, but they’ve added a twist which I shall not divulge here, because it was too much fun figuring it out. Stay until after GLaDOS’ song for a mini scene with Wheatly and Space Core.