Voice Studio was released as a free
application for kinect as a way for Microsoft to improve the audio recognition of the Kinect Sensor. It comes available for download through the Apps tab at the Xbox Home menu.
This is not so much a game but a means of voluntary research for microsoft, although, it does offer an easy 50G for completion of all 8 tracks; and best of all, it requires no skill and only takes 2.5 hours at most to complete.
Each track consists of 30+ commands or phrases such as "Xbox Bing Search" or "How was the weather in Davenport on Tuesday?"
Simply saying the phrases is sufficent and after you have finished the set number of phrases you must save and submit to recieve credit.
In the end this is a win/win situation. You help microsoft improve products and earn some easy gamerscore in the process. Happy Hunting
Edit: Credit to Odd for pointing out only 8 tracks.