|This article is non-canon.|
The subject matter of this article does not take place in the "real" Half-Life and Portal universe and is considered non-canon.
This article is about the demo. For the short film, see Half-Life: Uplink (film).
Despite being labelled as the demo version of the game, Uplink features a brand new chapter not found in the full game. The player takes control of Gordon Freeman in an alternate timeline. The game begins at the entrance to the Lambda Reactor Complex, 48 hours after the "containment failure". Here, the player meets a scientist and a security guard who wish to enter the complex and escape, but they can't open the door until "all-clear" signal is sent to the United States Nuclear Regulatory Commission. The signal can't be sent from the console, because the bombardment has damaged the cables.
The player is given a task to reach the transmitter dome and reconfigure the transmitter manually. There is a high amount of radiation in the dome area, and only the player can survive it because of his protective suit. The player is trapped in a large room with a Gargantua at the end of the demo, and can not escape. The G-Man can be seen watching from a window and walking away. The screen fades to black as the Gargantua comes closer. A message appears on the screen: "Current evaluation: uplink completed. Require further data."
Contrary to the popular belief, Uplink isn't a chapter that was cut from Half-Life. It features brand new levels, and utilizes some of the cut content from the final game. It is loosely based on an idea from the cut chapter, Communications Center. It was created over a couple of week span by John Guthrie and Kelly Bailey, without any code support. According to Marc Laidlaw, they had two design goals. The first was to introduce new players to the essence of the Half-Life experience. The second was to give current Half-Life players a brand new experience.
|“||By the time we finished Half-Life, we wanted to streamline the development process. The Uplink mission pack tested that out. One person built the world, another did all the entity work to create a whole experience; a handful of people who put it together with audio that we had left over. There were a bunch of scenes in Half-Life that we wanted to do and weren't able to pull off. In some cases we already had audio. So Uplink was a separate mission about tuning the antennae to the satellite you launched when it was up there. From there we thought, 'Let's build the next game this way.'||”|
|– Marc Laidlaw|
Uplink was originally released as a standalone demo, and was later included in several bundles as a mod for Half-Life. It is not available on Steam, but it can still be obtained from the internet. It was ported to PlayStation 2, and was released as an add-on on a PlayStation Underground demo disc in the June 2002 issue of the Official PlayStation Magazine. It can be played by entering a code from the Cheat Codes menu in the Options. The code is: Triangle, Square, Left, Right, Circle, X, Up, Down. This unlocks the Extras menu in the Options. The player can insert the disc from this menu to play the game.
 Behind the scenes
The training portion of the game was included in the demo. The game uses the Half-Life soundtrack. Vague Voices plays at the beginning, and later when the player sees Gargantua through a crack in a wall. Diabolical Adrenaline Guitar plays during the surprise attack in the dome. The same premise for the chapter was later reused in Surface Call in Half-Life: Decay. There is a scene where the Marines use a blow torch to open a sealed door at the dome. This inspired the creation of the HECU Engineer class in Half-Life: Opposing Force.
 In modding
- Uplink Addon seamlessly adds the Uplink levels into the gameflow of Half-Life itself, along with some minor content additions.
- A third-party remake of Uplink for Source called Black Mesa: Uplink was released on December 17, 2012. It was built using assets from the mod Black Mesa, itself a third-party remake of Half-Life.