I just played the first "hardcore" Kinect game. Sitting down, even.

Even in its incomplete state, Twisted Pixel's The Gunstringer is the best evidence that Microsoft's motion sensing tech can make possible a (so far) really fun game that already plays great and responds to subtle, natural movements with high precision. It's a game where you control a marionette with one hand and shoot with the other, and I can't imagine the experience feeling more authentic.