This is a good Sonic cartoon, yet...
This is in all, a good cartoon you did! Nice animation here and there, along with nice effects that you used flash for. However, I know a lot have said this, but you really did toss Sonic into the zone of Dragonball Z. For those who say it's nothing like it - it is. Hell, I think a scene was even ripped from one of the Dragonball Z movies. (Brolly smacking Vegeta into a rock)
Super Sonic was pretty exellent, as well as Hyper/Super Shadow, but it felt just the same as it would be as a Super Sayajin. (though technically Super Sonic does share a lot of the same attributes) It could be how they were fighting. Bang, smash, pow! With out these elements, a fight would be boring - this movie had them. Blood and gore threw off the Sonic feel, as well as tellaporting and high flying.
Still though, well done! =D