Portal is a single player 3D puzzle game that revolutionized puzzle games. Released by Valve in 2007, Portal introduces players to the Aperture Science Laboratories. Their players will take on the role of Chell and a human who has been subjected to tests at the laboratories. These tests are administered by an unhinged artificial intelligence named GLaDOS. These tests use the portal gun, a gun that opens a small wormhole between two places. With the portal gun, players will solve puzzles that involve moving themselves and other objects through the wormholes.