Yep, that means the original game, its sequel, the two Half-Life 2 "episodes", the various Half-Life based multiplayer modes and more are all on sale. You can even get the Half-Life complete pack which throws in Team Fortress Classic in one bundle for a mere $21.99 during the sale.
City of Heroes Ultra Mode Screenshots_thumbnail.jpg "Dragon Age: Origins - Awakening")
Dragon Age: Origins - Awakening
Primal Carnage Screenshots_thumbnail.jpg "Theatre of War 2: Kursk 1943")
Theatre of War 2: Kursk 1943
Victoria 2
Dungeon Defense
Dungeons & Dragons Online: Eberron Unlimited Screenshots
Boot Disk: Return to Castle Wolfenstein-(10)_thumbnail.jpg "LEGO Harry Potter: Years 1-4 Screenshots")
LEGO Harry Potter: Years 1-4 Screenshots
