Sesame Street: Once Upon a Monster is a video game developed by Double Fine Productions and published by Warner Bros. Interactive Entertainment in conjunction with Sesame Workshop. The game was released on October 11, 2011 for the Xbox 360 console. Players use the Kinect controller to control the Muppet characters Cookie Monster and Elmo and new characters Marco and Seamus as they sing and dance. Though Once Upon a Monster represents Double Fine's first foray into licensed property, the title started as one of four smaller titles, alongside Costume Quest, Stacking, and Iron Brigade, during an "Amnesia Fortnight" period during Brütal Legend, and was later found to be easily adapted to the Sesame Street property. The original prototype of the game, titled Happy Song, was released for Microso