Shortly after, Sonic travels to , a celestial body that appears over Never Lake for one month a year. Here, the story deepens:
In a final, desperate battle in space (Doomsday Zone), Sonic uses the Chaos Emeralds to destroy the Death Egg once and for all. DLC Content Expansion
The overarching narrative, unified by new animated cutscenes, follows the "Classic Sonic" saga: 1. The Genesis of a Hero (Sonic the Hedgehog)