Portal 2
The single-player portion of Portal 2 introduces dynamic characters, fresh puzzle elements, and a larger set of devious test chambers. Players explore areas of the Aperture Science Labs and reunite with GLaDOS, the murderous computer companion.
The two-player mode features a separate campaign with unique story, test chambers, and two new player characters. This mode forces players to reconsider everything they thought they knew about portals.
Portal 2 contains a multiplayer option in the form of a two-player co-op mode. This is playable both locally and online, with split-screen functionality available in local play and in select places during online play. Players assume the role of one of two robotic characters, Atlas or P-body, both new to the franchise. These two have separated from the control of GLaDOS and so must survive its anger, divvied out in the form puzzles, obstacles and misdirection. Each player has control of their own portal gun, which they use to platform through the game levels, avoiding its dangers and relying on each other.
The portal gun creates temporary passages through solid surfaces, allowing for creative platforming and multiple possible means of clearing a level. The game also requires the player to solve puzzles at times to clear sections of levels. In addition to point-to-point movement through portals, players can also utilize other means of movement of themselves and various objects.
These include: using the momentum of portal movement to make jumps to open positions like ledges; tractor beams; and special propulsion/repulsion gels that can be carried or stored.
