Sound Energy mixes a simple color-matching game of collection/avoidance with a little bit of musical interaction to create a superb multimedia experience. You control a transparent orb that can change color from purple to blue to gray. By clicking the mouse you can switch colors and absorb pieces that match your color. Build up combos to earn a high score and keep the background music shifting as you play!

Source: http://jayisgames.com/archives/2007/07/sound_energy.php