Half Life : Opposing Force (Trailer)

This 1999 standalone expansion plunges you into the Black Mesa incident as Corporal Adrian Shephard, a U.S. Marine, offering a fresh perspective on the original events. As a shooter, platformer, and puzzle experience, you fight through the facility using military gear while encountering the new alien faction, Race X, alongside Xen forces and black operations units. It is fully playable without the base game, focusing entirely on Shephard's isolated survival and his cryptic encounters with the G-Man.