Well for starters, it's way oversized for a sig. One thing I don't like about it is the random brightness in the top right corner. You can no light source up there, if anything it should be dark. Your light comes from those light beams you have scattered, which I also think you overuse in your artwork. But I guess for this theme it fits.
And one more thing I noticed is your two light beam things are different shades of blue. Match those up for a better flowing sig.
So: Size, and lighting.