Compared to most first-person shooters of the time, which relied on cut-scene intermissions to detail their plotlines, Half-Life 's story is told entirely by means of scripted sequences, keeping the player in control of the first-person viewpoint. Unlike its peers at the time, Half-Life used scripted sequences, such as a Bullsquid ramming down a door, to advance major plot points. Half-Life is a first-person shooter that requires the player to perform combat tasks and puzzle solving to advance through the game. In this scene, the player must bypass a dam reservoir guarded by an Apache helicopter, a group of soldiers, and a cannon emplacement. Half-Life has had a notable cultural impact with its community mods and sequels spawning a large fanbase and cult following. Half-Life was followed by the 2004 sequel Half-Life 2, which also received critical acclaim. By 14 July 2007, the Half-Life franchise as a whole had sold over 20 million units. Half-Life had sold eight million copies by 16 November 2004, and 9.3 million copies by December 2008. 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 praised 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 id Software's 'Quake' game engine with code portions from id Tech 2 engine called GoldSrc. The game had its first major public appearance at the 1997 Electronic Entertainment Expo. Sierra On-Line eventually signed the game after expressing interest in making a 3D action game. Valve, set up by former Microsoft employees, had difficulty finding a publisher for the game, with many believing that it was too ambitious a project. Gordon Freeman, a theoretical physicist who must fight his way out of a secret underground research facility whose research and experiments into teleportation technology have gone disastrously wrong. In Half-Life, players assume the role of Dr. First released in 1998 by Sierra Studios for Windows PCs, the game was also released for the PlayStation 2 Mac OS X and Linux ports became available in January 2013. Half-Life is a science fiction video game developed by Valve Corporation, the company's debut product and the first in the Half-Life series. Microsoft Windows, PlayStation 2, Linux, Mac OS X

Half life e3 1997