“Well, for our next big title we were going to focus on a game programmed with adaptive difficulty. But, all the outrage surrounding Left 4 Dead 2 said that, for what it was, our work wasn’t being appreciated. So we decided not to improve the engine further, and just shelve it. Then, the idea was tossed around introducing RPG elements into a co-operative FPS. But-if you’ll remember, a lot of customers got very uptight about the unlocks in TF2; that they just weren’t easy enough to get, and they were unbalanced. So doing anything surprising with the genre, after all the whining and manpower we decided was a waste, might as well been like shooting ourselves in the foot.”
— Gabe Newell - 4th Quarter, 2010
