The most challenging part of Sonic's updated design isn't revealed in this teaser: his eyes. The filmmakers struggled with how best to depict Sonic's eyes because often he's only seen with one, and that wouldn't translate well to the live-action movie.
"I don't think SEGA was entirely happy with the eye decision, but these sorts of things you go, 'It's going to look weird if we don't do this.' But everything is a discussion, and that's kind of the goal, which is to only change what's necessary and stay true to the rest of it," said Miller. "He's not going to feel like a Pixar character would because I don't think that's the right aesthetic to make it feel like part of our world."