On the Steam download service only, not on disc.
Full list follows..
Back to the Future: The Game
Tales of Monkey Island Complete Pack
Sam & Max: Season One to Three
Bone: Out From Boneville
Bone: The Great Cow Race
Telltale Texas Hold ‘Em
Strong Bad's Cool Game for Attractive People: Season 1
Wallace & Gromit’s Grand Adventures
Puzzle Agent
Poker Night at the Inventory
Hector: Badge of Carnage
http://store.steampowered.com/sub/8679/
