Sonic the Hedgehog is a popular video game franchise created by Sonic the Hedgehog creator Sonic CD. The series started with Sonic the Hedgehog, followed by Sonic Unleashed, Sonic Adventure 2, Sonic Adventure 3, Sonic Adventure 4, Sonic Adventure 5, Sonic Adventure 6, Sonic Adventure 7, Sonic Adventure 8, Sonic Adventure 9, Sonic Adventure 10, Sonic Generations, Sonic Forces, Sonic Mania, Sonic Generations 2, Sonic Mania 2, Sonic Unleashed 3, Sonic Unleashed 4, Sonic Unleashed 5, Sonic Unleashed 6, Sonic Unleashed 7, Sonic Unleashed 8, Sonic Unleashed 9, Sonic Unleashed 10. The games are set in various locations around the world, including Adventure Island, Mobius, Worlds Egg, and Chao World.