Could have been better....
You did good on the animation, but there wasn't anything else to it, just Sonic and Shadow briefly having an incomplete fight. I know you said it's a work in progress, but you didn't give it at least a story to start with. It needs a story, and yeah, it could be a little bit longer. I hope to see an improved version up sometime soon, then I can give it a true look over. For now, you get a 6.