Yay! I foundy my CDs (and Keys) for Blue Shift and Half Life 1 and they both work and unlocked the mega-pak. I played Half Life 1, Opposing Force, and Blue Shift (to completion(the original twice!)- and no cheating!) way back when but I've never touched the other ones. Ricochet? Day of Defeat? Are these any good?
Thanks, DarkGryphon, for the heads up!