Portal 2

Portal 2 is the sequel to Portal. First hinted in the update made to Portal in March 2010 as part of the Portal ARG, it was announced on March 5, 2010 to be released in fall 2010, but was later announced on June 9, 2010 as delayed until an unspecified date in 2011, until it was said to be released on February 9, 2011. This date was again delayed to April 19.

Portal 2 was previewed in the twelve-page cover story of the April 2010 issue of Game Informer, revealing some plot details and new gameplay features. It was also confirmed that GLaDOS was indeed still alive, and would return as the main antagonist. In addition, Game Informer and other sources confirmed a co-op mode for up to two players with its own separate campaign. The co-op campaign was said to have its separate credits, and would take place after the single player story. Valve was also scheduled to unveil the Portal 2 World Premiere on June 14, at their E3 2010 press conference, but later canceled the showing of Portal 2 on the 14th through a humorous e-mail, to be replaced with a "surprise". The game was shown in the form of a demo at Valve's own booth instead, and on June 15, the first Portal 2 trailer was shown during the Sony press conference, with the "surprise" apparently being its release on the PlayStation 3 console, which was originally not the case.

Characters
Arranged by roles.
 * Chell
 * ATLAS and P-body
 * GLaDOS
 * Wheatley (Intelligence Dampening Sphere)
 * Aperture Science Sentry Turret
 * Cave Johnson (voice only)
 * Caroline (voice only)
 * Doug Rattmann (scribblings only)
 * Space Core
 * Adventure Core ("Rick")
 * Factual Core

Gameplay
The gameplay of Portal 2 is based on its predecessor Portal, where the player, with the use of portals, solves puzzles. New gameplay elements such as Mobility Gels, the Aerial Faith Plate and the Thermal Discouragement Beam were implemented as means for the player to master in order to solve puzzles.

Chell no longer wears the Advanced Knee Replacement, but instead suited in the new Aperture Science Long Fall Boots. Combat plays a slightly larger role than in the last game, seeing as Chell is always meeting with enemies along the way.

Co-op campaign
Cooperative play is a new game mode introduced to Portal 2. The campaign features two characters, ATLAS and P-body. The two players must work together to pass tests and areas outside the test chambers. The developers implemented robotic characters in order to ease explanation of a respawning system, giving the story explanation that humans could not be trusted.

The gameplay is very similar to single-player mode, with the addition of object-specific buttons and tools to aid in cooperative play, as well as 8 gestures.

Development
As mentioned in The Final Hours of Portal 2, Portal 2 stemmed from F-STOP, which originally was a prequel to the first game set during Cave Johnson's era. F-STOP was not to feature portals; what remains of it in the final game is the Enrichment Shafts.

In 2007, Kim Swift stated that future Portal developments would depend on the community's reactions, saying, "We're still playing it by ear at this point, figuring out if we want to do multi-player next, or Portal 2, or release map packs." On January 31, 2008, Lombardi confirmed that "more Portal" would be forthcoming, and promised that the additional content would not just be "more puzzles"; an interview with Kim Swift on February 21, 2008 revealed that a full sequel, Portal 2, would be coming. Swift also stated that the team creating the Portal sequel were deciding upon the design they should implement and that a multiplayer Portal "from a technology standpoint is possible", though Swift had previously stated they tried a Portal multiplayer deathmatch variant, but admitted that "it's less fun than you'd think."

On June 10, 2008, Kotaku reported that Valve was seeking voice actors for the character role of Aperture Science CEO Cave Johnson and suggested that the second game may be a prequel to the Portal events. However, it was later suggested on Kombo.com it could be a sequel, with Johnson as another AI.

On April 8, 2011, lead writer Chet Faliszek gave an interview to Beefyjack where he discusses a variety of topics, including allusions to how Portal 2's story will fit into the overall Half Life universe and the secret to Valve's success when it comes to producing games being lots of playtesting.

On April 13, 2011, Doug Lombardi, Valve's VP of Marketing, posted details of Portal 2's PS3 Steam integration on the official US Playstation Blog. He noted that it will "offer cross-platform matchmaking, gameplay, friends, chat, and achievements" and will also allow players to save their progress, in both the co-op and single-player mode, to the Steam Cloud, which means gamers can continue any saved game on the PS3. Achievements will sync up as well. All in all, these features will, according to Lombardi, make the PS3 version of Portal 2 "the best console version of the game."

Achievements and trophies
Portal 2 has 51 PC achievements, 50 Xbox 360 achievements with a total of 1000 Gamerscore points, and 51 trophies ; 42 bronze trophies, 5 silver trophies, 3 gold trophies and 1 platinum trophy.

Reception
Portal 2 has received universally positive reviews and currently holds a 95/100 on Metacritic. Critics praised nearly every aspect of it, particularly its use of humor. Many also find the game's difficulty at just the right level, saying it's not so hard that it's frustrating, and yet hard enough that you get a sense of success after completing a level.

Sixense DLC
A level pack was made available for those that purchased the Razer Hydra motion controller. It consists of six normal chambers and seven advanced chambers. With the DLC installed, the portal gun gains several new abilities. The new features work in both the extra levels and the main campaign, but are disabled in the co-op campaign.

The first new ability is One to One, which allows the player to rotate a held object in three dimensions, as well as hold it further away through the use of an energy beam. The beam does not have infinite range, only allowing the object to be held about three or four panel lengths away. This allows for precision aiming with the Weighted Pivot Cube, and can be used to place cubes on buttons that would otherwise be out of reach.

The second ability is portal surfing. This ability allows the player to move their portals after placing them. Unlike One to One, this works at any distance. Portals can be tilted to either side and moved along walls, so long as the surface in question can support a portal. This is a necessary aspect of several tests, which have portal surfaces too short for a portal to form on vertically, necessitating that it be dragged there horizontally. Dragging portals also allows the player to move themselves or objects across a room while suspended in an Excursion Funnel. Tilting a portal connected to a Hard Light Bridge allows the bridge to be turned on its side as a shield if necessary, or moved along with the player to block a turret. The spreading of Mobility Gels can also be controlled with much greater ease.

The final ability is scaling, which allows the portal gun to alter the dimensions of a special Scaling Cube. The cube can be shrunk to fit through a tight space, stretched out and flattened to serve as a bridge, or even enlarged to cover multiple buttons at once. In addition, the scaling cube's mass increases or decreases in proportion to its size. This allows a sufficiently enlarged cube to smash through panes of glass an ordinary cube could not, as well as crush turrets or the player if it lands on them.

Portal 2 DLC #1
A currently unnamed DLC is being developed for Portal 2. Although little is known at this time, what is known is that it will launch across all platforms free of charge. It will also add a currently undefined challenge mode to both Single Player and Multiplayer.