What small extraterrestrial body does Sonic protect in Sonic CD?

Sonic protects Little Planet in Sonic CD. The small extraterrestrial body appears over Never Lake during the last month of each year, drawing Sonic into Dr. Robotnik’s latest scheme.

Robotnik chains Little Planet to a mountain and transforms it into a fortress. He seeks its seven Time Stones, while Sonic travels through the planet’s past, present, and possible futures to stop him. The game’s time-travel system makes Little Planet more than a setting: its condition changes depending on the player’s actions.

Little Planet is also the setting for Sonic’s confrontations with Metal Sonic and Robotnik, and Amy Rose is rescued there. Players can create “good futures” by traveling to the past and destroying enemy transporters. Collecting all seven Time Stones also guarantees the game’s best ending.

The name can be confused with South Island or Angel Island, locations from other Sonic adventures. Little Planet is specifically the temporary, time-altering world central to Sonic CD.