So, I found this Tut in Gimptalk and I made a sig with it.... I've still got a long way to go and this is my first step. So... CnC??? Maybe???? Or something?
The colors of the render don´t match the ones of the background, too, it doesn´t have blending, and blur the background and sharpen the character and you have depth.
Render is low-quality and needs to be blended and th text is HUGE. The render should be the focal point. And must I constantly remind people of the rule of thirds?
The text is terrible, the KH text goes with virtually nothing, and it is way to big. The background does not match the render at all. Find a single colour scheme and stick with it. The render isn't very good. Add some depth you need to practice with blur/sharpen as well as lighting to add depth and flow.