This allows complex "flinging" maneuvers to be used to cross wide gaps or perform other feats to reach the exit for each test chamber.

A number of other mechanics, such as lasers, light bridges, high energy pellets, buttons, cubes, tractor funnels and turrets, exist to aid or hinder the player's goal to reach the exit.

In addition to the challenging puzzle elements, both games are praised for their dark humor, written by Erik Wolpaw, Chet Faliszek, and Jay Pinkerton, voice work by actors Ellen McLain, Stephen Merchant, and J. K. Simmons.

Aperture Science was founded by Cave Johnson (voiced by J.K. Simmons) and originally sought to make shower curtains for the military.

Johnson acquired the rights to a disused salt mine in the Upper Peninsula of Michigan, where they started building a labyrinthine set of offices, laboratories, facilities, and test chambers.

During this time, Johnson became poisoned from exposure to moon dust, a key component of the paint needed to support portal technology, and became increasingly deranged.

GLaDOS was built to control the facility and monitor the tests, but researchers found that the computer had villainous tendencies, threatening to kill the entire staff before it was shut down in time.

Portal 2 takes place an unknown number of years after the events of the first game; the Aperture facility has fallen into disrepair without GLaDOS.

They return to the surface where they are forced to defeat Wheatley before his ineptitude with the Aperture systems causes the facility reactors to become critical and explode.

Instead, she turns to two robots of her own creation, Atlas and P-Body, to locate a mythical store of additional human subjects kept in cryogenic sleep for her to continue testing on.

The player-characters are able to withstand large drops, but can be killed by falling in the toxic water of the facility, crushed to death, passing through laser grids, or fired on repeatedly by turrets.

Each chamber has an exit door that must be reached, often requiring that certain conditions have been met such as having weighed down a large button with a "Weighted Cube", effectively a crate.

Commonly, one uses gravity to build up their momentum when they fall into a portal, which flings them out of the other side to gain speed and distance that normal jumping and running could not generate.

Portals will also allow light and other objects to transfer through them, and numerous puzzles involve using portals to manipulate bouncing energy balls, lasers, "hard light" bridges, and tractor beams to access new locations or direct objects to specific receptacles that must be activated to open the level's exit.

The games' credit sequences feature the songs "Still Alive" and "Want You Gone" composed by Jonathan Coulton, and, in its original form, sung by Ellen McLain in the GLaDOS voice.

[4] Valve originally saw Portal as an experimental game to be included with its upcoming compilation, The Orange Box, alongside its release of Half-Life 2: Episode Two and Team Fortress 2.

[5] To give the game character, a minimal story, tied loosely with the Half-Life world, was written by Valve's Erik Wolpaw.

[6] Portal's release with The Orange Box received near-universal praise, with the standalone game earning an aggregate Metacritic rating of 90 out of 100.

[12][13][14][15] Valve included a co-operative play mode, based on their own observations and stories from players about working out the solutions to Portal's puzzles in a group environment.

[19] Valve has continued to support the game through the release of two separate downloadable content packages, one introducing a new co-operative campaign,[20][21] and a second that incorporated an easy-to-learn level editor that allowed players to make their own test chambers and share these through the Steam Workshop to others.

[26] Portal was initially released in October 2007 as part of a compilation game called The Orange Box, alongside Half-Life 2 and its two episodes and Team Fortress 2.

Valve considered including Portal as a bonus feature of the compilation; the game was purposely kept short such that if it did not meet expectations, players would have the rest of the content of The Orange Box as a "safety net".

[32] In September 2022, Nvidia announced it would release an updated version of Portal with real-time ray tracing, as a free DLC for owners of the original game on PC.

It received acclaim for its gameplay, pacing, dark humor, writing, the voice work of McLain, Merchant, and Simmons, and its challenging but surmountable learning curve.

[39] The initial iPad release was written by Keighley with work by Joe Zeff Design, a studio that had also produced digital applications for Time magazine.

He escapes GLaDOS's initial neurotoxin attack, but suffers symptoms as his schizophrenia medication runs out, causing hallucinations of his Weighted Companion Cube talking.

Valve had approached Cryptozoic with the core concepts of the board game, which the publisher found only needed small modifications in gameplay for the purpose of balance.

It was described as a "room-scale" VR experience, consisting of about a dozen small experimental experiences that highlight the use of VR; such include experiencing a fully panoramic view that has been stitched together from a number of photographs, a physics game where the player attempts to launch personality cores into piles of boxes using a catapult, and a bow-and-arrow based game.

It is a tech demo set in the Portal universe that showcases the functions of the hand, knuckle, and finger tracking technology used by the Valve Index.

The effort is built on a standalone "Puzzle Maker" that incorporates the level editor for Portal 2 that was released as free content for the game in early 2012.