Sierra Half-Life Opposing Force

Half-Life Opposing Force is the official add-on from Sierra that takes you back to the same location as the original Half-Life however this time you are playing the opposite side as the original. If you are familiar with the original Half-Life you will recall that you played the role of Freeman a Scientist who after a catastrophe experiment ended up finding out about a dark military secret. Now you are back in the action however this time you play the role of one of the military troops set to stop Freeman however for an unknown reason.