This is better than the first
I enjoyed watching this, this flash is better and more original than the first.
Graphics: Better sprites and better usage. They don't jump as much, but the after images near the end didn't look so good.
Style: More random, original, unique and other stuff (I'm not the expert here).
Sound: Music was good, but some of the effects were a bit too annoying.
Violence: This flash has it's good violent moments, but not enough to get a ten (or a nine).
Interactivity: Ending selection again, that's it. Good work on making it go well though. You should try easter eggs that unlock endings for you.
Humour: It was better than that of the first, and more random. I like random XD.
Overall: between an eight and a nine, this deserves a nine, to make it a ten I would probably advise you to use more characters (like a race of all the Sonic's friends or perhaps, a match where Tails helps sonic as Eggmandid shadow).
Good luck if you decide to make number 3.