If I have a chance to created an augmented space I would play with Projection mapping and human shadow.
In this sketch, the user will stand in front of a projector and Kinect camera. The projector will cast the player's shadow on the wall. Then, a virtual shadow will be projected on the wall. This shadow will walk toward the player shadow and trigger the user to act like it. The Kinect will detect the location and movement of the player.
In this sketch, I'm interested to play with the partially real world. The player's shadow was real in the beginning then it will be manipulated by the virtual world.