Very cool
Graphics - 7. It looked a little choppy when they were running. Maybe try to smoothen down the sprites too? Also I didn't see the logo :(
Style - 6. I don't prefer Sonic vs Shadow. I seen too many and it looked like any other S vs Sh flash.
Sound - 10. Where do you get such wonderful sounds? Send me!
Violence - 10. It explains what the flash is all about.
Interactivity - 10. If it's full of action. Why not?
Humor - 0. Didn't find anything funny. Wrong mood to look at funny flash either.
Overall - 8. -1 For being not unique (Sonic vs Shadow lol) and -1 for...having such a small screen I guess. It's a personal preference.