Portal 2

Portal 2
Developer	Valve
Publisher	Valve
Release date	April 19, 2011
Engine	Source
Platforms	Windows, macOS, Linux, PlayStation 3, Xbox 360

Portal 2 is the sequel to Portal, the puzzle-platform game originally released as part of The Orange Box. It features significant upgrades across multiple aspects of the game, including its engine, graphics, physics, and gameplay systems.

It also features a larger single-player campaign, new characters, a co-op mode and an in-game level editor.

Its development cycle was particularly complex, going through multiple different storylines and design choices, especially in its behind-the-scenes maps, resulting in a substantial amount of development material and unused content.

Development builds

See Proto:Portal 2 for an index of known development builds.

References

Portal series
Portal	Portal 2	Portal 3