“It’s a special case of the team came off the project with a head full of ideas for what to do next,” said Doug.
“They got a lot more feedback when the game went out and basically they sat down, did a whiteboard exercise and put a plan together for the sequel.
“The pitched the game to a bunch of us [Valve] and it seemed like a great idea.”
So that’s that.
Watch the full interview after the break.