1998. HALF-LIFE sends a shock through the game industry with its combination of pounding action and continuous, immersive storytelling. Valve's debut title wins more than 50 game-of-the-year awards on its way to being named "Best PC Game Ever" by PC Gamer, and launches a franchise with more than eight million retail units sold...
Weren’t the two episodes free?
Maybe there was some special or package deal, but no.
Not unless they had some special bundle for HL2 I can’t remember.
Ep1 had to be purchased. Ep2 came with The Orange Box (which also contained TF2 and Portal 1 as well as Richochet, though it wasn’t advertised).