You'd never know it by the millions of copies that Guitar Hero sells on an annual basis, but just a few years ago rhythm and music games such as Frequency, Amplitude, and Vib Ribbon were part of a fledgling genre that garnered plenty of critical attention but failed to sell very well. Audiosurf, which at the time of this review is available only as a downloadable title via Steam for $9.95, is a game that harks back to those days. You don't so much play the music stored on your computer as you experience it. The gameplay is simple but addictive. And while you'll have the most fun competing with friends for high scores, you can lose yourself in your music for extended periods and have a great time, too.