A look behind the scenes of Portal

A new video put together by Valve News Network -- a YouTube channel devoted to the games of the Seattle-based developer -- delivers a comprehensive, behind-the-scenes look at the evolution of the original Portal, from its genesis as student project Narbacular Drop through a variety of iterations and on to the final game.

The video is cobbled together from a variety of early builds of the game, and offers an unusual look at the early days of such a high-profile game.

Hungry for more Portal? Gamasutra spoke to Kim Swift and Erik Wolpaw, the game's lead designer and lead writer, in 2008.