Half-Life: Opposing Force

 
As an expansion pack for Half-Life, Opposing Force is a first-person shooter. The overall gameplay of Opposing Force does not significantly differ from that of Half-Life: players are required to navigate through the game’s levels, fight hostile non-player characters and solve a variety of puzzles to advance.[3] The game continues Half-Life’s methods of an unbroken narrative. The player sees everything through the first person perspective of the protagonist and remains in control of the player character for almost all of the game.