Here's a short but sweet video demonstration of Mert Akbal's Avian Flight Simulator game build using Unity. Game mechanics are simple enough. Gesture with your arms in a flying motion in order to control the height at which the butterfly climbs. Angle your torso in different positions to change the flight path direction as you fly around.
If anything, it's a great work out for those flabby arms developed over the holiday season. Definitely a less embarrassing work out then the shake weight!