It’s been a long time. How have you been? I’ve been really busy being dead. You know... after you murdered me?
Portal 2 is definitely one of the best games I've ever played. Valve has once again outdone themselves.
This review focuses mainly on the gameplay of Portal 2, in an attempt to keep story details and other spoilers to a minimum.
A great sequel to Portal. The game is now a full game, with a singleplayer campaign lasting around 8-12 hours. Anyone who tells you they beat it in 4 hours, or it's as long as the original is either lying, or used cheats/console codes.
The Co-Op has it's own story, and last an additional 3 or so hours.
There's a lot more humor than the original, with plenty of dark humor akin to Portal. This game got me laughing almost right off the bat.
The puzzle's aren't incredibly hard, so you shouldn't need a walkthrough for (at least most of)the game. That isn't to say the game is easy though. To complete this game, you really have to think with portals.
Although this is likely to be the best game of 2011, even if it is only the end of Q2 of the year at the time of this writing, every game does have at least a few minor letdowns:
The Pneumatic Diversity Vent seen in the games trailers are not featured in the game. This isn't a big deal at all, but the idea would still've made for some good chambers.
Some of the very complicated chambers, such as those in the Propulsion gel trailers, are also not featured in the game. This too isn't a huge deal, but it would've been great to play these. Valve's releasing some free for all platforms DLC, so hopefully chambers such as these will be featured.
For PC version mappers, the Portal 2 SDK wasn't released with the game as Valve usually does, so a little bit of sneaky-ness had to be applied to find a way to map for it. (UPDATE: The official SDK has been released.)
This was a very, cut-short Portal 2 review. Sorry if it may sound opinionated. I tried to keep spoilers out of this, so it was fairly vague.