Very nice! There's just a few things that I noticed that you could maybe change.
The first thing would be adding more space to the right so that the character and his weapon have more space. This also leads to the meat not being in the complete center of the picture, which I feel make the scen a bit less static.
Then, there's the character's weapon which glows in this strong green. Since the rest is in warmer, earthy tones, it kind of pull the eyes towards the weapon, away from the main action. So I think having a more muted or yellowish green would help it blend with the rest a bit more and not attract the eye as much away form the action.
That's pretty much all I got. I think it'sa pretty cool illustration 
