This is Guard Duty. Put your feet in the shoes of Barney Calhoun, a security guard at the Black Mesa Research Facility who has no idea that the next few hours are going to change his life forever. Re-live the exciting adventure of Blue Shift, now re-created in the award winning Source engine.
Few words about Greenlight, progress and more about Guard Duty and Operation Black Mesa.
greenlight incoming for blue shift and opposing force remakes !