The animation was incredibly slow-placed which made it felt pretty boring, especially when it was 5:10 minutes long. There was no sound and I guess you did meant to add music in it but somehow it wasn't there. I guess there was pretty much a story in it, but you should add dialogue in it next time. (I like the ending with Metal Knuckles popping up, though.)
You should use Adobe Flash to animate sprites instead moving the characters with your mouse on "Epic Sonic Creator 4". If you can't afford Flash then I'm sure there are other free animation software out there where you can animate sprites.
Keep on improving with your sprite animation, though!