This game promotes profound and clever thinking in gamers. Apart from the beautifully designed puzzles -- all of them a perfect blend of increasing complexity and satisfyingly new and fresh ideas -- Portal 2's single player campaign is accompanied by a rich, mysterious plotline that will act as incentive to quickly complete the test chamber ahead to see what will happen next.
Multiplayer is a whole other story. And I actually mean that literally. It is backed by a completely different story, though the experience isn't heavily based around the plot. With two portal guns, a new door is opened with the potential for hundreds and hundreds of new test chambers, but more importantly, the multiplayer experience allows for hours of fun and entertainment with friends and family.
In short, Portal 2 is beast.