From the introduction:
A beautiful world, serene and majestic in its natural state. The natives of this world, Mobius, and the creatures who thrive in the landscapes have lived in tune with this world for as long as they’ve remembered. Even as pastoral as it may be, it has its wonders. The monthly arrival of the “Little Planet” over Never Lake...the mysterious Angel Islands floating in the sky...even simply the various tunnels and shuttle loops of the Green Hill Zone.
Not all see the wonders and simply admire them with an appreciative eye, however. There is someone who wishes to exploit the innocent creatures of Mobius and its people(the Mobians) as both slaves and even energy sources…a madman named Dr. Robotnik. He dreams of a world ruled by machinery and tyranny, where nature is simply his resource to become an unstoppable king. He will be opposed, however, by a certain blue hedgehog in South Island. From there, the battle will escalate from the fields of Green Hill to even low orbit in the grand space station known as the Death Egg. But, that isn’t quite your story. Whether you join the battle against Dr. Eggman, explore the Zones of Mobius, or even attempt to raise an army of your own...this is the first step to your own story. Still, you’ll start with that first face-off.