An asteroid is heading for Turtle Town and Robotnik offers to save it, but only if Sonic agrees to play in the Robolympics against him and his robots.

Sonic becomes the sheriff of Tranquil Gulch, in hopes of keeping Robotnik's robots from harassing the locals.

Robotnik goes time-traveling to find the four Chaos Emeralds that bestow the user unlimited power. His first stop is the time of Blackbeard the Pirate, where he enlists the pirate's help to find the first emerald.

Robotnik's next stop in his time-travel is the Middle Ages, where the second emerald is. Sonic follows him, but Robotnik, with the unwilling help of a local wizard, obtains the emerald and takes over the kingdom.

In his next time-travel stop, Robotnik plans on erasing Sonic's family tree in order to get the third emerald.

Despite the intervention of Sonic and Tails, Robotnik obtains the fourth and final emerald in prehistory. With the emeralds gathered together, Robotnik uses them to become an all-powerful being.

Sonic and Tails babysit a trio of unruly baby beavers who end up being abducted by Scratch and Grounder.

Sonic and Tails get arrested for speeding due to Robotnik's nefarious hypnotizing scheme.

Sonic and Tails enter a car race in order to save an orphanage that Robotnik threatens to shut down.

Sonic, Tails and a group of mole miners are hit by Robotnik's shrink ray and must work together to reverse the effects.

Robotnik takes control of the local amusement park on Sonic's birthday and uses it to try to finish him off.

Sonic and Tails help a mermaid hedgehog named Merna save her underwater city from the wrath of Captain John Paul Memo.