Well, some of the strands look like they are going through his neck, so I suggest you change that. Other than that, the text (especially that there are two copies, looks sort of lame), I suggest going to 1001 fonts, or dafont, and getting some pimp ones. One last thing, it's a personal peeve of mine, that I hate when people add effects to a video game that weren't already their, without using the game engine. So the rocket does nothing for me. The colours also look a bit washed out, I suggest darkening the render.
well theres simply the matter of the sig size requiment... 200x500. and i suggest you add a little more in the background of the right side.. maybe a cool symbol like breaking benjamin's or maybe a face like disturbed.. i like it though.. but i agree with turbo about adding those effects.. those dont really work the best but i don't mind them