Sonic Shuffle

The story begins when Sonic, Tails, Knuckles, and Amy find themselves in an umfamiliar place called Maginaryworld. They meet a small fairy, named Lumina, who asks them for help. She explains that Maginaryworld is the world of people's dreams, and that the source of power there is the Perfect Precioustone. A villain named Void has shattered the Perfect Precioustone into many pieces, resulting in chaos in every part of the world. Lumina Flowlight and the rest of Maginaryworld are counting on Sonic to restore it and bring Lumina back, who mysteriously disappeared along with the Perfect Precioustone.