I just love this super creative game developed by Andy Wallace. Built in openFrameworks, Doodle Defense is a take on the classic tower defense styled game but "Kinectified" for that 2012 touch. The cool part about this design is that you can draw on a white board and have the enemies move according to your hand drawn layout.
The Kinect is used to capture the board image while a projector animates the "enemy" pieces. The idea is to prevent them from reaching the other end of the white board by using an assortment of different coloured markers.