Half-Life: Blue Shift is the second official expansion for Half-Life, made by Gearbox Software and released in a stand-alone package that also included Half-Life: Opposing Force. Half-Life: Blue Shift wasn't well received due to its short playtime, lack of multi-player, and lack of new weapons or enemies. Like Half-Life: Opposing Force, the expansion casts players in a new role; that of Security Guard Barney Calhoun.
Half-Life: Blue Shift was originally a bonus level for the now-cancelled Dreamcast version of Half-Life, but was later ported to the PC. It was also included as part of the Half-Life: Generation compilation.