After Dr. Eggman and his doppelganger; Eggman Nega steal the legendary Sol Emeralds, gems similar to the Chaos Emeralds, from Blaze's home dimension, this flings her to Sonic's universe and creates a tear in space-time that threatens both worlds. Now it's up to Blaze to hunt down the Sol Emeralds and for Sonic to stop the tear or else the two worlds will collide.

When theives steal a Chaos Emerald, Sonic and his friends must learn how to learn the skills of the Extreme Gear in order to stop Dr. Eggman from stealing a legendary treasure.

Sonic must protect Soleanna's princess from Eggman so the mad scientist won't take over the world. Shadow must stop Mephiles before Drake gets his hands on a dark being and its powers. Newcomer Silver must prevent a disaster from happeing in his futuristic home. It's a three-way battle royal to save everything everyone loves!

Sonic, Tails, Stella and Chloe are flung to Blaze the Cat's home world, the Sol Dimension, after an accident while flying the X-Tornado over the ocean. Upon arriving in this world, the heroes befriend Marine and her chocolate lab puppy friend Tidal, a young and friendly raccoon who aspires to explore the world. Upon encountering Blaze, the group joins her in her quest to stop a group of villainous robots headed by Captain Whisker who desire to steal the Jeweled Scepter, which is the key to the almighty "Power of the Stars", and a treasure from her homeland. All the while trying to uncover a sinister force at play.

Sonic discovers a legend regarding an artifact known as the "Ark of the Cosmos", an item that can take matter and use it to control gravity. However, the Babylon Rogues, Sonic's well-known rivals, are also after the legendary artifact. This sets off a war over who gets the artifact, now leading them to settle their dispute by having an Extreme Gear competition.

Following a failed attempt by Sonic to defeat Dr. Eggman in space, Eggman shatters the world with the power of the Chaos Emeralds, unleashing two earthbound entities known as Light and Dark Gaia and infusing Sonic with a state called 'the Werehog' at night. Now Sonic must navigate various continents while accompanied by Light Gaia, nicknamed "Chip", to restore the Chaos Emeralds' power and repair the planet.

The past and present collide in a pursuit of answers. When Sonic is framed for a crime he did not commit, he and his friends must discover the mysteries of Project Shadow and the Silverbolts' past to stop the wicked Drake from destroying the world.

When Eggman creates a space amusement park as a ploy to capture innocent yet powerful aliens called Wisps in order use their powers to rule the world, Sonic, Tails and Stella must work with the aliens to foil Eggman's plan.

Past and present collide in a frantic chase for truth and understanding! Shadow is haunted by the memories of battles fought and lives lost. But these nightmares aren't just lingering pain! They're prompted by a force Shadow, his sister and their friends thought was destroyed.

Follow Sonic the Hedgehog as he joins a resistance force to take back the planet, after Dr. Eggman's Eggman Empire took over 99% of it with the help of Eggman's newest assistant; Starline, with his twisted ideals of caring for one's health, and Eggman's newest lackey; Infinite, through his usage of the Phantom Ruby. Along the way, three new resistance members learn the meaning of courage and unity.