Doodle Jump is about as basic as you can get - you jump on platforms up, up, and up, while avoiding broken platforms and aliens that you can shoot. If you miss a platform, you plummet to your death. Game over. Movement is done by manipulating the accelerometer, and you fire by touching the screen.
How this translates to Kinect is not revealed in the press release. If you have to jump to make the alien jump, you're in for quite a workout. What is plain is that this would be one of the oddest XBLA games. Ever.