Portal is a puzzle game set in an underground facility called Aperture Laboratories around the year 2010. The facility is controlled by an AI system named GLaDOS. You are a test subject, Chell, who has to solve different challenges with the use of a quantum tunneling device; a portal gun. The sequel, Portal 2, is set an indeterminate amount of time, thousands of years, after the first. Note - The website contains spoilers from this point on. The Aperture facility has fallen into disarray, and you now have to escape the ruins with the help of a robot, Wheatley. Power changes hands, and it becomes a race to stop Wheatley from destroying the whole of Aperture. Throughout the game, you learn the history of the facility and its founder, Cave Johnson.Â
The images are links to purchase the game on Steam.
Portal 1 is on the left, 2 on the right.