Half-Life 2: Portal is basically “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.” Video after the break. Click here for more pictures.

Rather than being released at retail, Portal and Team Fortress 2 are included with the release of Half-Life 2’s Orange Box