Dr. Robotnik organizes a bounty hunters convention to capture Sonic but when it doesn't go to plan, Robotnik builds Scratch and Grounder to be part of the new Super Special Sonic Search and Smash Squad (or SSSSS Squad for short).
Desperate to get workers to build a Robotnik statue, Dr. Robotnik opens Casino Night Zone with his pal Smiley but when Sonic stops Scratch and Grounder, Robotnik traps Tails so Sonic has to make a choice to save his pal.
While Scratch and Grounder try to catch Sonic using a Suction plate, two aliens, one being a prince, crash lands on Mobius. Sonic meets the prince when he finds out that the prince's baby brother would blow up Mobius which Sonic must save.
Dr. Robotnik with help of a tied up professor invents Gismo Gas that makes objects larger; while Sonic and Tails are in Weiner-Ville eating chili-dogs the machine explodes causing Tails to become a giant which Sonic must find the cure.
Robotnik invents a ray that ages people but when Sonic and Tails are having free samples in Robotnik's Food Factory, Grounder presses the wrong button that turns Sonic, Tails and by mistake Robotnik into babies.
When Dr. Robotnik plans to change the Sonic 12 Mobium bill to a Robotnik one, a salesman comes and offers magical items but Robotnik throws him out causing Coconuts to have an idea to catch Sonic using the salesman's goods.
After Robotnik finds out that it is Sonic's birthday, Sonic is bored until someone gave him a ticket to Mobiusland (a theme park). However Robotnik took over and it got changed to Robotnikland which Sonic must enjoy his present.
After a failed chili-dog trap, Scratch and Grounder find an old martial arts teacher which Robotnik kidnaps and uses his knowledge to create and turn Scratch and Grounder into Robo-Ninjas to stop Sonic.