Beloved developer Valve has released lifetime retail sales figures for some of its more popular games, including the Half-Life and Counter-Strike series, revealing that the studio has sold over 32.8 million games since the 1998 release of the first Half-Life.

Sales from Valve's digital distribution client are not factored in, with the figures only accounting for worldwide retail sales. With Half-Life 2, Valve began simultaneously releasing all of its PC games at retail and via Steam. The numbers were originally printed in the November issue of Game Informer, then republished by Gamasutra.

Furthermore, it was not specified if the figures of multiplatform games--Half-Life, Half-Life 2, The Orange Box--included both PC and console sales, or just PC.

• Half-Life (Valve) / 1998 - 9.3 Million
• Half-Life: Opposing Force (PC, Gearbox) / 1999 - 1.1 Million
• Half-Life: Blue Shift (PC, Gearbox) / 2001 - 800,000
  
  
• Counter-Strike (PC, Valve) / 2000 - 4.2 Million
• Counter-Strike: Condition Zero (PC, Valve) / 2004 - 2.9 Million... Read more

Here it is, the first of our reviews of The Orange Box. Valve's Half-Life 2: Episode Two is an incredible game, and possibly the best single-player straight FPS to be released this year. Valve's design principles are more refined than ever, and the game introduces some of the most significant new elements the Half-Life series has seen yet--all in a game that's longer, denser, and packed with more variety than the already-great Half-Life 2: Episode One. Read our full spoiler-free review.

With neither length nor the release frequency of the Half-Life 2 "episodes" being particularly episodic, it has fallen to the narrative and plot elemets in Episode Two to live up to the designator. Episode One took criticism for lacking tangible plot relative to Half-Life 2; whereas Episode One was largely driven by a general sense of urgency, Episode Two is much more practically driven by concrete plot motivations in the style of Half-Life 2.