Before you lies the threshold to a new world of ultimate adventure — and ultimate challenge. A world where you must think before acting, plan your every move and outsmart your way through devious chambers. In this game, your mental abilities are your best means of survival. Following in the critically acclaimed footsteps of the original Portal, this all-new campaign opens the door to mind-testing puzzles, with an immersive story and never-before-seen environments throwing new obstacles in your path. Are you brave enough to enter?Rejoin GLaDOS, the occasionally murderous computer companion who guided you through the original game as you explore the all-new test chambers of Portal 2. Advanced gaming physics, an intricate storyline and original music immerse you more fully than ever in the addictive gameplay made famous by 2007's Game of the Year Portal. Explore exciting new areas within Aperture Science Labs. Cooperate with an accomplice in a totally unique two-player campaign mode. Get ready to reconsider everything you thought you knew about portals. Success will require you not just to act, but to think with skill.

Experience all the thrilling action in the Left 4 Dead: Game of the Year Edition. The world has been overrun by creatures of horror, and you are one of only a handful of surviving humans. From the eerie, remote countryside to the asphalt expanse of shadowy urban centers, the streets and fields teem with zombies and mutants intent on the destruction of all humans. Harness your weapons and prepare for the fight of your life as you struggle to destroy the monstrous creatures before they destroy you.Left 4 Dead deposits you in a terrifying modern world swarming with zombies and "Boss Infected" mutants with horrifying superhuman abilities. Team up with up to three additional players in Survivor Co-op mode as you assume the role of Survivors struggling against your own potentially imminent extinction, completing four sprawling campaigns, each with five new maps that will take you into both deadly urban environments and sinister rural areas. Or explore the possibilities of Versus mode, in which you can play as either a Survivor or one of four types of Boss Infected mutants, each with astonishing features, such as a 50' tongue lasso or a belly full of explosive methane gas. Prepare to face allies and enemies driven by advanced artificial intelligence that makes each outing into the Left 4 Dead universe one filled with unique and potentially deadly surprises. This special Left 4 Dead: Game of the Year Edition comes complete with the Left 4 Dead Survival Pack filled with exclusive content, including a new four-person Survival mode that pits you against swarms of zombies and two additional Versus campaigns with five maps for additional four-on-four multiplayer action.