Half-Life: Blue Shift

The Academy never prepared you for this...

The official expansion pack for PC GamerÂ’s "Best Game Ever" is here. Scramble to keep the scientists and yourself alive as you extinguish the many hostile attempts on your life.

In Blue ShiftÂ’, return to Black Mesa as the security guard who allied with Gordon Freeman in the original, award-winning thriller. Or become Adrian Shephard, the military specialist assigned to eliminate Gordon Freeman in the highly acclaimed Opposing Force.

Automatically upgrade all your Half-Life® weapons and characters with new high definition content using the High Definition Pack. Learn more about the incidents at Black Mesa, and explore new areas of this mysterious government facility. Battle up to 32 opponents from around the world in Capture the Flag and more Half-Life® online games.

This is definitely not just another day on the job.

http://www.sierra.com/product.do?gamePlatformId=33

Source:

Sierra Entertainment Official Website

Made by Gearbox Software and originally released in 2001 as an add-on to Half-Life, Blue Shift is a return to the Black Mesa Research Facility in which you play as Barney Calhoun, the security guard sidekick who helped Gordon out of so many sticky situations.

Source:

Steam