Already convinced by previous versions (1 and 2) ultimately this 3rd version is required reliability and especially new. A truly interactive game where you can really move and sweat (far ahead of Wii Fit which simply relax us by example and therefore not really a game of fitness).
With the technology of the Kinect there is much less dimprécisions in movements, it is much better detected, so fewer cheats and more calories burned ...
Little more to music, there already are many, but for people who will spend time fully on the game, it would take more.