Portal 2 is a 2011 first-person puzzle-platform game developed and published by Valve Corporation and the sequel to 2007's Portal. In the single-player campaign, the player controls Chell, awoken from suspended animation after many years, who must navigate the now-dilapidated Aperture Science Enrichment Center during its reconstruction by the reactivated supercomputer GLaDOS.
Portal 2 also includes a two-player cooperative mode, in which the robotic player-characters Atlas and P-Body are each given a portal gun and are required to work together to solve puzzles. The game retains Portal's gameplay elements and adds new features, such as tractor beams, laser redirection, bridges made of light, and paint-like 'gels' accelerating the player's speed, allowing the player to jump higher or place portals on any surface.
Although some reviewers initially expressed concerns about the difficulty of expanding Portal into a full sequel, Portal 2 received critical acclaim, particularly for its writing, pacing, and dark humor. The voice work of was also praised, as were the new gameplay elements, the challenging but surmountable learning curve, and the additional cooperative mode. Some journalists ranked Portal 2 among the best games of 2011, and several named it their Game of the Year. Portal 2 has since been hailed as one of the greatest games of all time.
- "Think With Portals" – Official website
- Portal 2 on Valvesoftware.com
- Portal 2 on Portal Wiki and Half-Life Wiki