My senior project in college was an interactive projector wall installation in NYC PS347, a public school catering to deaf children. I used an Xbox Kinect sensor and OpenCV computer vision libraries to make two programs in C++. One was an interactive fish tank (including my own drawings for the fish and plants) and the other was built on an existing FFT visualizer library, but I made it react to your body movements and play music clips.
An archive of the code I wrote is on my Github Page.