Its gameplay influenced the design of first-person shooters for years after its release and it is widely considered to be one of the greatest computer games of all time. On its release, critics hailed its overall presentation and numerous scripted sequences, and it won over 50 PC Game of the Year awards. Designed for Windows, the game uses a heavily modified version of the Quake engine called GoldSrc (Gold Source). The game had its first major public appearance at the 1997 Electronic Entertainment Expo. Sierra On-Line eventually signed the game after expressing interests in making a 3D action game.
Mike Harrington, a former Microsoft employee who founded Valve Corporation, had difficulty finding a publisher for the game, with many believing that it was 'too ambitious' project. Gordon Freeman, a theoretical physicist and also the main protagonist who must fight his way out of Black Mesa facility which its experiments had gone terribly wrong, teleporting aliens from another world (Xen).
