Half-Life: Day One · Rare Pre-Release Demo

Half-Life: Day One is a pre-release demo of Half-Life, a first-person shooter done by Valve in 1998. Day One was exclusively done for OEM partners and has been shipped with several graphics cards. It includes about the first fifth of the final game, but it’s still unpolished and has some minor differences and issues. The first official demo for the general public was Half-Life: Uplink, which has been released a few months after the final game.