Sonic and Tails are back with three times the fun and three times the trouble! Dr. Robotnik is building the ultimate super-weapon with the help of Knuckles, but you can stop him by getting the Chaos Emeralds first. Rip across snow and water on Sonic's new jet skateboard or zip underwater in Tails' "Sea Fox". But look out - Nack the Weasel is after the Emeralds, too!

While the evil genius Dr. Robotnik is testing the ultmate destructive weapon, one of his assistants makes a mistake causing his lab to explode and scattering five Chaos Emeralds across the planet Mobius.