Is this an actual Xbox 360 Kinect game or "just" a very well made "Kinect hack" for the PC??
By the way, there a great (non-Kinect) game on Xbox Live Community Games called Groov. (That's not a typo, it's Groov without an "e".) It's like Geometry Wars but your actions create the music! It only costs 80 MS points (around 60p/$1) and is well worth it.