@Maddus: I realize my edits to the OP last night were not actually saved so I can now see why you might think the guy is "waving his arm looking for the cursor". We constructed what is known as the "invisible touch screen." Imagine an invisible surface in front of you...you can touch it at any point to interact with the display.
@Bas: We user tested push to select and it didn't seem to work well at all. Of course, at that time I was using the OpenNI SDK,so I'm not sure if the unreliability was attributed to that. My guess is not. We found that the "push" gesture opened up a lot of variability. Some envisioned a push as simply tapping their fingers forward...others exaggerated their entire hand forward. Ultimately, you can't support both instances because that will just get confusing (might complicating other scenarios in which subtle gestures might come about). Not requiring a push removes consideration of the z-axis with restricts the space of actions down to something more reasonable (2D in a 3D world). It's also no surprise that the Xbox team and most games limit it to a "hold to select".
But, I do love how Kinect is used in Your Shape...unfortunately, I picked up that game towards the end of the final push of our project. I would have loved to implement their style of push to select as that was just brilliant. If you look closely (if the video doesn't suck as much), we did carry over the progress-bar-like feedback from Your Shape when you hold over an item. If we had more time, we would have definitely explored incorporating the angle of the user's arm in the selection process.