I have quite a few things to say so I'll just put them in order :
A the intro, during the explosion, we can clearly see ''make more gift at gif-soup'' or something. It's just weird to see that during an animation.
The intro song could have ended in a fade out instead of being brutally muted.
There's was many punctuation mistake and 1-2 blatant spelling mistakes, careful for those thing.
Some fonts were impossible to read due to certain colors (brown, black...), you could add a white bubble behind them to erase this problem.
I don't mind the super sayan transformation but it's a bit cliché. It's not bad but some people may hate it.
Things felt a bit rushed, people that don't really know each others just becomes allies in a matter of seconds.
You could have used some Sonic sound effects... You know, because it's a sonic animation. For example, at the end, before they fight, you could have used a voice clip of Shadow saying ''let's do this'' , ''this is the ultimate power'' or something like that.
And last of all... Why is it in the game section? It should be on the animation section.
As a game, I give it 0/5.
A an animation, I give it 2/5.