Like they successfully managed to fuck up
ALL of his proportions AND his demeanor.
Look at his OG artwork (which clearly is what the movie is basing off of) in comparison.
Big head
small body
connected eyes
thin lanky legs
thin lanky arms
big feet and hands
big protuding nose
strong posture with an inviting pose
confident/intimidating demeanor (try and make the face he's making in the above pic and you'll understand what I mean)
His head is too small
His body is too long and large
His feet are too small
His eyes are too far apart - not connected
His nose is tiny
His demeanor is too friendly
His body language is too relaxed
Even in the more modern versions of Sonic all of the original traits properly:
His head is significantly bigger than his body
His feet and hands are huge
His demeanor is intimidating and competitive
His body language is strong
His eyes are connected
His nose is long and protrudes out of his face
The movie Sonic legit looks like a kid in a costume. Like why bother changing his look at all when the entire subject matter is insane. You have a anthropomorphic hedgehog that can run at the speed of light like come on now.