Half-Life: Uplink

1999, developed by Valve

Half-Life: Uplink is a demo version of Valve's 1998 first-person shooter computer game Half-Life. Uplink features many of the common enemies, characters, and weapons from the full game, but unlike the first Half-Life demo and the Half-Life 2 demo, the location and scenario in this demonstration do not appear in Half-Life. The Uplink chapters were cut during Half-Life's development phase and roughly fit in prior to or during the Lambda Core chapter; they were, however, strongly revised for the demo release. Uplink also includes the same Hazard Course from the full release of Half-Life. It was also included on "Official PlayStation Magazine Disc 57" as a bonus unlock if you entered a cheat into the PS2 version of Half-Life and swapped the discs.