​Unlike many other games at the time, Half-Life features no cutscenes; the player has uninterrupted control of Freeman, and the story is told through scripted sequences seen through his eyes. Valve co-founder Gabe Newell said the team had wanted to create an immersive world rather than a "shooting gallery".
Half-Life: Opposing Force is an expansion pack for Valve Software's science fiction first-person shooter video game Half-Life. The game was developed by Gearbox Software and Valve Corporation and published by Sierra Entertainment on November 19, 1999. Opposing Force is the first expansion for Half-Life and was first announced in April 1999.