Half-Life: Opposing Force

The first official "expansion pack" for the 1998 Game of the Year, Half-Life: Opposing Force puts you in the shoes of Colonel Adrian Shephard, a member of the military force sent in to clean up the Black Mesa facility at the same time Gordon Freeman was making his escape in the original game. With 11 new episodes, loads of scripted sequences, the ability to command other soldiers, and a pack of "All-Star" multiplayer maps done by leading industry level designers make, Opposing Force has shaped up as one of the best mission packs in recent memory.