The art, released by Tacit Sign Studio, features several scenes that were either cut or tweaked in the final cut of Sonic 3. One clearly stands out, however: Metal Sonic standing next to Emperor Eggman ruling over a post-apocalyptic future, something that would have presumably been part of an after-credits stinger.

New Sonic the Hedgehog 3 concept art showcases scenes which didn't make the final cut and drops some big hints about what's heading our way in the next movie after that big post-credits scene

Concept art for the Sonic the Hedgehog 3 film has been released, revealing cut content and a look at secret characters from the post-credits scene. The images are from Chinese designers at Tian He Yan Studio,