I went into Portal 2 expecting more of that same great experience I had in Portal. A few second into the game I could tell that this sequel was more then just a cosmetic makeover of its predecessor.
It is hard to imagine what goes on in the minds of the talented folks at Valve. I would like to think that Gabe Newell himself trains each employee individually on creativity. Each unique game play mechanism introduced throughout Portal 2 is used to solve multiple puzzles that require the player to think outside the box. Some game play mechanisms from the first game have been replaced, like the energy orbs being replaced with by lasers, and some mechanisms remain, such as weighted cubes and buttons. The courses are also cleverly designed to be solvable by players of any skill level. If a player is ever lost on where to go next in some of the more spacious courses, the game is expertly lit to draw the players attention to the next place he or she must reach. All of the creativity is a definite improvement over the first game.
The visuals of the game still heavily resemble that of a modern Source game, but are much more entertaining to look at then the first Portal. The art direction of a Aperture Science Lab overgrown by nature is an appealing one. It even ads a much needed freshness to the two maps you revisit from the first game early on. The most subtle lighting is given the very utmost detail throughout the game, and Aperture Laboratories is also detailed down to the pieces that are crumbling off of it. Valve really worked hard to show that the Source Engine is still a viable platform to develop on this generation.
The characters and story also improve tenfold. Voice acting is superbly cast and preformed across the board, and Valve still chose to go with a voiceless main character to act more as a vessel for the player to attend this journey. The story includes all the elements that you would expect out of a good movie: solid plot, a twist in the journey, and multiple climaxing events.
Unlike its predecessor this game is no meme generator. Yet, the single player alone for Portal 2 may all be playable in one sitting, but is definitely worth the price of admission.