Don't like it one bit, your just making a gloopy background (like paint mixed with colours) and just sticking pictures and text on, you havn't really put much into it, if you look at other peoples work you'll see a great difference.
How long did this piece take you?
I know saying to spend alot of time into a work might seem boring to you, but its sometimes the only way you'll get a good finish.
Seriously, i don't like it at all, change background, blend the pictures and dont just put a glow around them.
The text sucks.
You'll find it easier concentrating on one characer at a time, then you won't have trouble getting colours to go with them all, if you had sonic you could get away with just using blue, but it'd have to be different shades of blue.
At the moment you have blue red, orange pink to work with, pretty hard but can be acomplished.
Try one character at a time, after your first one work on a same type of theme and do the others singularly with different colours and backgrounds obviously.
/Tofas
-Sorry about grammar and general typing skills, recently i havn't been making much sence while typing for one reason or another.