It might be good
The problem is that you should not really submit tests to this website. It might not be so much of a test as a preview (as the title suggests) but it's still an incomplete movie and it doesn't cause much anticipation. I think it's kind of obvious who is going to fight Sonic in this. I believe it's another version of Sonic. A pity you could have not had the character shadowed or anything. I think this actually wouldn't be that bad of a full flash.
The lines drawn aren't too bad, but the spritework needs more. It seems like you could make this better by having a lot more action. I will always regret never knowing how to give a submission a "Replay" button so I can't criticize you for that. You should look into someone who knows more to understand it. It's a bit too short for a preview too.