I love the shading .. It as if elite is bad and spartan is good! And i love the sketchy kind of look the screen has! Nice job! =]
I think the effect looks generally good, but there is a little too much dead space in the middle. I suggest either making them appear a bit closer or adding some scenery. I really don't know, I'm not an expert on this.
The Gravity Hammer doesn't flow very well for me in this Screen shot. It looks a bit weird and I think a Sword would've been better. Also if he would've crouched. Great Screen shot though, looking at the theming and colours.