|Portal 2: The Official Guide|
But I got nearly a thousand visitors to my Portal 2 lens yesterday, and have been having great fun collecting Portal 2 Quotes! There are many awesome quotes from the various very funny trailers, the main single player storyline featuring Chell, and from the Robot duo co-op option.
Basically, Chell has been in stasis (check out the prequel/sequel comic linking Portal and Portal 2) and now there are two AI's - Wheatley and GLaDOS. There's also personality named Caroline who is downloaded into GLaDOS, a boss battle very similar to the ending of Portal, and a clash of the AI titans over Chell.
Otherwise, lots of trap-puzzle rooms, some new toys, and a lot more talking! And turrets and the beloved Weighted Companion Cube of course. GLaDOS steals the show again, naturally (or is that 'mechanically'?), and there's a new credits song from Jonathon Coulton ("Want You Gone") which is definitely growing on me, although it's not as funny as "Still Alive".
Because Portal was actually a test game, it was mainly designed to be purely functional. And short. Portal 2 is longer and prettier - Chell went through some dramatic redesigns in the concept art stage, but is back in her orange jumpsuit, and similar features (with better graphics).
Oh, and they did mention cake... but the mention was a lie.
Total gameplay is around nine hours for the single player Chell campaign and about five hours for the co-op campaign. Like the original Portal, the replayability factor isn't quite as high as it could be, once you know the answers to the puzzles. It's available for PC, Mac, Xbox 360 and Playstation 3.