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...
20th anniversary celebration
https://www.half-life.com/en/halflife2/20th
Comes with a long list of fixes and updates.
Episode 1 and 2 are now bundled with HL2.