In Sonic Riders, Dr. Eggman challenges Sonic and his friends to a Worldwide Grand Prix, and the prize for coming out on top is an ultra-rare Chaos Emerald! Gliding on air boards – which are performance-oriented for each playable character – gamers will experience a heightened sense of Extreme sports-style racing tension as Sonic and his pals perform tricks and stunts over treacherous wide-open terrain.