imo:
Border is too thick.
Text, it doesnt suit, remove it.
Creat depth by apply image>smart sharpen (mess around with settings)> erase the BG
Looks a bit noisy, try to remove tht noise
i kind of agree.. but not fully. and i only slightly agree about the noise.
amongst the bg the noise seems like floating embers off of a fire, however on his body and his right arm/the gun pointing down, the noise is kinda conflicting.. its white (maybe?) and doesnt seem to have a source of origin.. if the noise amongst the (robot?) matched the color of the bg it'd be great so it would follow suit with my floating embers thought..
other than that great job. i dont know what you did on the left of the image, but i like it. definitely more of that.
i dont know if its the image or my shitty eye sight but his left shoulder seems to be the most blurry / depth added, which is really well thought out, giving the effect of his arm being pulled back, but the gun of it coming forward like he's going to shove it down your throat.
awesome.