Yeah, I haven't been able to *ahem* "acquire" Photoshop yet, so I'm making due. I already know the basics, just gotta work a little harder for it in GIMP.
Good use of blur, but some of it is more blurred than the rest. Example, the 3 spikes at the right. The first on is really blurred, the next isn't much and the last is in the middle, so its a bit inconsistent. Other than that it is good. A border would look nice too.
its really ovr blurred you could have easily achieved a better depth with some lighting effects and LIGHT blurring