"By evolving our development process to an episodic approach, we're able to reduce risk from things such as schedule and funding and invest more in new types of gameplay," said Gabe Newell, president and co-founder of Valve. "This allows us to produce innovative titles such as Portal and Team Fortress 2 and deliver them in a timely fashion to customers along with Episode Two."

Episode Two advances the 16-million unit selling franchise, as Valve's trilogy of episodic single player releases continues the award-winning story of Half-Life 2. Armed with new weaponry and vehicles, Dr. Gordon Freeman must race through a countryside riddled with an increasingly feirce Combine threat.

Team Fortress 2, an all-new version of the title that spawned team based multiplayer action games, features the most advanced graphics of any Source-based game released to date. Players choose from a range of unique character classes such as medic, spy, sniper, or engineer and must work together to complete a variety of tactical objectives.

Portal is a new type of single player game that changes how players approach, manipulate, and surmise the possibilities in a given environment in a manner similar to how the Gravity Gun changed our approach to how an object may be leveraged in any given situation.

Team Fortress 2 and Portal will be included with all retail and Steam versions of Episode Two for the PC. In addition, these products plus Half-Life 2 and Episode One will be available in one tremendous offering for the PC, Xbox 360 and PlayStation 3. New videos from Episode Two, Portal, and Team Fortress 2 will be released next week.