The overall effect is pretty nice.
The only thing I'd say is the image is just not hard to make.
I see a big highlight,so that easy,path tool and select and fill.
All those colourful lines are pretty easy too,just make the lines with path tool,alpha to selection,I'd make a new layer and overlay it after filling it in with a rainbow gradient and lowering the opacity..
The thing in the middle is just not clean,it looks like a massive explosion of brushes,it would look nice if you removed a bit of it and maybe making is more 'consistant'.
Anyway,overall it's nice,I'd say 8/10.