A 2011 first-person action/puzzle video game, developed by Valve Corporation. It is the sequel to Portal.
Portal 2 takes up from where Portal left off (more or less) and offers the same basic game play of puzzles that must be solved using the Aperture Science Portal Gun and objects found in the game world.
New elements have been added such as tractor beams, barriers, gel and a two player co-op mode.