Half-Life: Blue Shift

We're back in the Black Mesa compound yet again for the second "official" expansion for 1998's groundbreaking first-person shooter "Half-Life." Take the role of security guard Barney Calhoun who, like Gordon Freeman, is given the task of wiping out every nasty extraterrestrial or misled soldier who crosses his path. (Also includes the first HL expansion pack "Opposing Force.")