I've played (and finished) the original Portal on my Xbox 360. I really liked the game, and thought many times about having another go to listen to the developer commentary. However, I do not fancy another play-through using that wicked game-pad contraption.
Recently I picked up the PC version on steam. To my utter chagrin, it requires me to finish a chamber before being able to access the commentary. This would mean two entire play-throughs, which is a bit much even using keyboard and mouse.
Is there some way to convince the game that I've played it already and let me listen to the commentary unhindered?