G3P - Really cool uniform, really nice design. The logo on that metallic medal form looks great. Perhaps you need some wrinkles on the chest band, like the uniform on the torso part, only a comment 
Studio Monkey - Nice concept, the lighting looks cool. Maybe the texture of lines for the uniform is to much straight and looks odd. You can select that part of the uniform and use warp to deform the straight lines to follow contour of the body and wrinkles on the uniform (Edit / Transform /warp) Another method is to use liquify, advantage, more control. (Filters/Liquify).
Art2 - Nice concept. Like a lot the skin over the helmet detail 
ChaosShannon - Like the colored pencil style on your image, go with it. Perhaps you need to use a background with the same style, a bit on comic style, only a comment
J4q- Cool, really original concept. Maybe you need to put lighting on the background too look a bit less darker and a bit like red sky and gain more deep on your image.
Ataulfo - great update my friend. Amazing details on your concept. Maybe I prefere the feather headdress in your first image, to put a soft and curved contrat with all the straighten ornaments, only a comment Cheers!!
Yone - cool update. The tatoo and the cyber device on the face looks great !
Smuraikuroi - the palette looks nice. Waiting for more updates
Paperclip - Really great concept, a very cool approach, like a lot
Darkriddles - Cool update, looking nice. Maybe you need to put more contrast an lighting on your image, think is a bit dark now.
Diddle - Nice concept! The armor looks great. And like the expression of your character
Sadrack - Your concept looks really cool, Like a lot the “Cienpies” idea, great
Rhemrev - Great concept, very original, like a lot the expression. Cheers!
Diguera - Cool concept man! THe “Rastas” and skulls armor is a great touch! Cheers!
