L4D2 DLC based on Cabin in the Woods was planned at one time
Left 4 Dead 2 had some DLC planned at one time based on the films Cabin in the Woods, according to the movie's director Drew Goddard.
Speaking in an IAmA on Reddit, Goddard said if it weren't for financial issues at MGM, it would have happened.
"We actually were going to do a downloadable L4D2 expansion pack, where you'd fight in the Cabin world, but then MGM went bankrupt so the delay squashed it," he said. "But the people at Valve were still cool enough to let us use some of their monsters to fill the cubes in the background (I had a lot of cubes to fill.)
"By the way -- the game was gonna be amazing. You were gonna be able to play in both the upstairs "Cabin in the Woods" world and the downstairs "facility" world with all the monsters.
"Believe me, I HATE all video games based on movies, they always suck, but porting Cabin into Left For Dead felt like the right fit. It pains me that it didn't happen."
That honestly sounds as though it would have been rather cool.
Thanks, EvilAvatar.