Metal Depot is an unlockable area in Sonic Battle.
This is where the player fights Chaos Gamma in story mode. It is located in Gimme Shelter. The area is laid out horizontally, and is one of the longest stages in the game, making it easy for players to escape their enemies. Large amounts of platforms make pursuit difficult, especially for those with a bad jumping ability.
After waking up, Shadow teleports here to find information about Emerl.
Rouge comes here along with Shadow and Emerl. Shadow explains his similar birth and fate with Emerl and says that he is nothing but a weapon of destruction.
Emerl can come here to train with Gamma.