Alright.
Well it wasn't too bad, the movements weren't jerky, but could be smoother, maybe bump up the framerate and put some frames inbetween.
Also, add some more detail to it, it was basically just an outline, maybe add a bit of shading, some eyes. And it would've been a lot better, because if the name wasn't there it would've taken me a bit to realize it was sonic.
I really did not enjoy the moving background, it was only a 3 frame loop, and also wasn't very detailed. Also please don't make it last forever, there was really no point to that. anyways it was a decent animation, with a bit of flaws.