Eeehh..... my first sprite tag, and I'm not so sure about it... I didn't know what to do with the background: CnC?
Umm...I'm not too sure about this. There's too much background for me, and not enough colors. It's just basically kind of plain. I don't know much about sigs, so I'm afraid I can't tell you much on how to improve. All I can say is that it doesn't stand out much. Sorry.
Err, what are you trying to acomplish by cloning the Sonic sprite multible times? It confuses me. The checkboard texture in the background makes me think of paper sheets you use in math classes, so to me this is like a school motive with Sonic on it.
Sonic is mah thing D=, and this sig doesn´t makes justice to him, how you dare.... Now you are my new autoproclaimed enemy. Basically make it again, because everything looks a little messy and bizzare, I could give you a tut if you want, just PM me, and tell me what program you use.
Work on your smudging and don't rely so much on your filters cause I can tell that is what the background is. And you rendered the sprite way to much, it shouldn't be that noticeable. There is not flow to it either, you need to work to a lighting source and make sure things are atleast going in some general direction.