The film, written by Patrick Casey and Josh Miller, follows Sonic (voiced by Ben Schwartz) as he journeys to San Francisco with a small-town cop (James Marsden) so he can escape Eggman (Jim Carrey) and collect his missing rings. Additional cast members include Tika Sumpter, Adam Pally, and Neal McDonough, while Colleen O'Shaughnessey reprises her voice role as Tails from the games for a mid-credits scene cameo. Sonic was initially redesigned so he would be more realistic, with fur, new running shoes, two separate eyes, and a more humanlike physique. Sonic's redesign was met with backlash; it was criticized for not resembling the game design and described as evoking an uncanny valley-type of repulsive response from viewers. As such, the design was revised to better resemble the original.