From the back of the case
"Double the screens... double the excitement!
One screen's just not enough for Sonic the Hedgehog as he blasts his way onto the Nintendo DS and takes high-speed action gaming to a whole new level! In the first game to really push the DS to its limits, Sonic rushes, races, and dashes between BOTH screens with dizzying dives, near vertical curves, extreme jumps and brain-twisting loops over 14 massive levels! Prepare for a whole new dual screen experience, Sonic-style!
Dangerous boss levels challenge you in 3D combat.
Sonic rushes to the extremes on both DS screens!
Includes wireless play and [a new] mysterious female companion created exclusively for Sonic Rush!"