One of the most original and anticipated games returns on the Mac, PC, PlayStation 3 and XBox 360 with Portal 2 finally landing on our shelves. Originally based on the Half-life engine, this  game featured some of the most innovative gameplay in years as it allowed players to create their own portals in this first-person shooter inspired puzzler. More importantly, the developers of this sequel, Valve have managed to successfully build on their original premise and create a worthy successor that really makes the gamer think in order to solve these puzzles in the destroyed Aperture Science Labs.

Joining the player again is GLaDOS, an artificial intelligence who has been dubbed as the "occasionally murderous computer companion" who assisted the player in the first game. What makes Portal 2 even more unique is that the game supports a totally separate two player cooperative campaign which requires the players to truly work in conjunction.

Add in an engaging new story, some revamped game mechanics and good graphics and when I first put the game in, I thought to myself... I'm truly home again. For me, Portal 2 is less a first person shooter as opposed to a radical puzzler that really challenges the way we interpret physics. With that said, the problems that you encounter in Portal 2 and just like the original are something totally different which had me cursing on quite a few occasions when I got stuck.
 
The story of Portal 2 also fills in the blanks from the first game and truly opens up this universe with some of the plots from the original being resolved. Players still control Chell, the original protagonist from Portal 1 and from the very first moment you awake, things have really gone to hell since you last visited the Aperture Laboratories. The fist chapter of the game acts as a tutorial, teaching you the basic ins and outs of portal creation and more importantly, the physics of this universe.

You are also joined by Wheatly, a small orb shaped robot which time has not been very kind too as its databases seems a little rusty to say the least. Wheatly is brilliantly voiced by Stephen Merchant (The Ricky Gervais Show) who had me smiling on more than on occasion and definitely adds some much needed comedy relief. GLaDOS on the other hand is still as spooky and creepy as ever with her great one-liners such and sly remarks about you destroying the facility or just not being a very nice person. One minute the AI is oozing with praise, the next... it wants you dead. The conversations between Wheatly and GLaDOS is a pure treat to watch unfold as well.

The gameplay of Portal 2 will make the player feel ecstasy and despair at the same time. As you attempt to comprehend the strange physic bending puzzles in the game, sometimes you'll just kick yourself as the answer was staring you right in the face. The main object is to use your portal gun which basically shoots two different coloured portals that are linked together.  These allow you to access different areas in the game which can be quite a head spin at the start because they defy the physics of the real world. For example if you shot one portal on the floor and the other on the ceiling and you jumped in the portal on the floor, you would find yourself in an endless loop for eternity.

And then to give you a gamers headache, the title throws in all sorts of puzzles to help you reach your destination, such as moving cubes through portals to be placed on a touchpad to activate something like a stairwell or shooting portals to manipulate where a laser beam points. This is the beauty of Portal 2 and although sometimes extremely frustrating, when you do find a solution, you really feel good about it. Add in blobs and tractor beams and sometimes your brain is trying to figure out what's up and what's down.

Another thing about Portal is that it is quite addictive and after completing one section, I always wanted to play another and then another, hence the speedy review. If you do become stuck, Valve often leave many clues around such as posters with simplistic pictures explaining what you actually have to do. There's also Wheatly and GLaDOS who can also offer some assistance. However if the frustration is overbearing, the game uses an auto-save mechanism, so sometimes a few hours off or a day is enough to help your brain solve the puzzle.

Multiplayer has received a unique facelift in this game as Steam incorporates the console world onto their servers. In essence, this means cross-platform multiplayer so you could be playing against PC gamers or even Mac. This also includes chat as well. By purchasing the PS3 version, gamers of this console will be able to unlock the PC steam version of game. Valve have confirmed that additional DLC will be available in the future but for now, the game is more than ample.

However another highlight of the game is the co-operative mode which starts from right at the end of the original game and helps fill some of the gaps from what has happened from the end of number one to where the single-player game ends. I must admit that if you thought the single-player game was a total mindf**k, cooperative really ups the ante, especially as both players have portal guns which can make a total of four portals. Valve as devious as they are, ensure that without cooperation, you ain't going anywhere.

This is where headsets really come into play as you do need to talk out the puzzles between yourselves. If you don't have headsets, the game does contain enough basic communication options on the PS3 to almost get you through. Lastly, the two little robots that you control in the cooperative mode, Peabody and Atlas are such a treat to play and even though they have no facial features, they are full of emotions and GLaDOS really adds to their personalities.
 
Graphically, Portal 2 looks fantastic on the PS3 with its clean graphics that although quite Spartan at times on one hand, has some amazing detail on the other. It's a very strange amalgam that works perfectly in this title. The environment that you navigate is pure ingenious and Valve have really pushed their Source Technology to the limits. Even though the engine used in this game was incorporated into Half Life 2, it's received some much needed developer love here and the world of Portal really comes alive.

Seeing the crumbling Aperture Laboratories as mother nature attempts to claim it back is also a journey because once GLaDOS kicks into gear, she begins to change the environment just like the excellent sci-fi movie, Dark City as the laboratories come to live as this serial killer like AI begins to control the machines. Add in some really amazing special effects, especially with the portals and this works well with the gameplay that sucks you in right from the start. Featuring an original soundtrack, the music of Portal 2 helps sooth the savage gamer and fits well in this remarkable upside universe that would make M.C. Escher quite proud. Of course you cannot beat the great voice acting of both GLaDOS and Wheatly.

After completing Portal 2, it's great that Valve have continued on their original premise because this is the perfect game for those gamers caught in the doldrums of endless first person shooters, racers and sport games. Originality is the key here and Valve have succeeded on just about every surreal and cerebral level with its puzzles. The introduction of new characters into the story plus the wit and sarcasm of both Wheatley and my favourite AI creation in existence, GLaDOS truly create one of the most unique gaming experiences of 2011. Just make sure you leave your gun at the door when you play this one. Just be warned that this is the most frustrating game that I have ever played as well.