Sonic the Hedgehog 4: Episode Metal is an additional episode available for free to those who have purchased both Sonic the Hedgehog 4: Episode I as well as the upcoming Sonic the Hedgehog 4: Episode II on the same device for free. The extra episode will tie together the events of Sonic CD and those of Sonic 4, beginning with Metal Sonic's revival.
Episode Metal will allow players to play as Metal Sonic through the stages of Episode 1, as well as providing four exclusive levels unique to Sonic's robotic copy.