Well...
It's obvious that the times the animation quality dropped was because you couldn't find an appropiate sonic x sequence to trace. Noone dips in quality like that in an animation, you've clearly traced half the sequences in this. Please do something more original then just try stick together a bunch of traced sequences together and then draw horrible sequences in between. I even recognise half the sequences where you've traced from. You could of least ripped off the sounds of sonic X aswell so it didn't seem so cheap. Ahh well. You tried I guess.