Planet Freedom (惑星フリーダム Wakusei furīdamu?) is the main setting of Sonic the Hedgehog: The Movie. It is the home planet to Sonic, Tails, Dr. Robotnik and many others. The entire planet is unique in that it is split into two layers: the Land of the Sky and the Land of Darkness.
The populace of Planet Freedom ranges from anthropomorphic animals to normal human beings, though the term "human" is never used in the film. The planet is also home to a number of strange human-animal hybrids. These include Sara, the President's daughter, who appears to have cat-like features, including a tail, semi cat-like behavior and cat ears.
Planet Freedom is made up of two different regions referred to as "dimensions", that separates the planet into two different layers; the outer world that is called the Land of the Sky and the inner dimension that is called the Land of Darkness. Within these regions, several cities and other "Zones" can be found.
Land of the Sky
The Land of the Sky (天の大地 Ten no daichi?) is a region made of sky-bound islands and continents, making aircraft a necessity to move from place to place. All these landmasses are connected to a glacier which both anchors them to the planet's surface below and separates them from the Land of Darkness. Most of the planet's populace resides here, in a region of islands collectively known as South Island which is governed by the President. Apparently, long before the movie's plot, an unknown disaster forced the populace into the mountains, where they rebuilt their cities, becoming the Land of the Sky.
Beneath the continents lie rivers of magma that spread all over the planet like blood vessels. If the tip of the huge glacier was punctured by an explosion, the magma would rush to the surface and melt all the ice. This would cause the continents to separate from each other and the gravitational pull of the planet, sending them hurtling into space.
Land of Darkness
The Land of Darkness (闇の大地 Yami no daichi?) is the world underneath the Land of the Sky and is the actual surface of Planet Freedom. It is where Dr. Robotnik lives and Robotropolis can be found, as well as ruins of buildings crumbling into the sea. Befitting the area's setting, the planet's thick clouds and floating contients block out most of the sun's light. Despite its gloom, the land is quite verdant, though it is a bit rugged with ridges and mountains and is littered with deadly booby-traps and killer robots designed by Robotnik. The Land of Darkness can be accessed in two ways: by a whirlwind-like "portal" in the Land of the Sky, or by chancing into a warp zone; an extradimensional link between two locations.
Long ago, the residents of Planet Freedom lived on the surface, but their home city was destroyed by a disaster and the inhabitants were forced away. Finding the mountains of Planet Freedom high enough to reach the planet's atmosphere, the people relocated to the mountains, while the surface became increasingly polluted and dark. In this time, Robotnik took control of a large portion of the destroyed planet, building his city. Because its skies were shrouded by a blanket of smog and the cities were destroyed and decaying, the people of Planet Freedom gave the area its name.
Land of the Sky
Land of Darkness