Half-Life 1 Anthology - PC 4 exciting tiles in 1 great action-adventure compilation Survive killer aliens in Half-Life's plot-driven, complex world Explore restricted areas of mysterious government facility in Blue Shift Opposing Force offers new arsenal of weapons and 12+ multiplayer maps Team-based multiplayer game, Team Fortress Classic 4 exciting tiles in 1 great action-adventure compilation Survive killer aliens in Half-Life's plot-driven, complex world Explore restricted areas of mysterious government facility in Blue Shift Opposing Force offers new arsenal of weapons and 12+ multiplayer maps Team-based multiplayer game, Team Fortress Classic