The Valve News Network has taken on the task of telling the story of exactly how the game Portal came to life. We get to see how it started as something looking like Hexen, grew into something that looked like a Half-Life 2-puzzler and then took a new shape and became one of the very best puzzle games of all time. There was also a really strange steampunk design at one point.
"Today on Valve News Network, we go over the entire history of Portal, and talk about many things that were left in Beta or cut entirely. Most of what is seen in this video has never been seen before by the public, and I am very happy to be able to share it with you today."
Check out the full video on YouTube.