Portal 2

Portal 2 is a first-person puzzle game developed by Valve Corporation and released on April 19, 2011 on Steam, PS3 and Xbox 360. It was published by Valve Corporation in digital form and by Electronic Arts in physical form.

Its plot directly follows the first game's, taking place in the Half-Life universe. You play as Chell, a test subject in a research facility formerly ran by the company Aperture Science, but taken over by an evil AI that turned upon its creators, GladOS.