Hey, people! Lovely images you did there Blywulf.
Although I'm new around here, I would like to start to participate. Here are some suggestions on how to improve your image even further(it's pretty sketchy. Sorry):
Basically what I changed was the anatomy that seem to be pretty much human to me, except for a couple of features... I have no idea if we have a post/wiki entry detailing these aliens. I most certainly could not find it, but I'm guessing Ortnok are reptilian based humanoids? If that's the case I think it would add a lot of character if we actually borrowed elements from the reptiles anatomy, instead of just using their scales/absence of nose.
Also in this position, since the anatomy is mostly human, his mouth would probably be opened, because of his back muscles lifting his head.
I felt it was lacking depth - as in contrasted color regions - and volumes seem a bit "pillow shaded" and blurry to me.
The injuries seemed to be missing from the dead alien as before he died, he was probably shot or pierced in some way. Anyway it's just a suggestion.
I mean that's something that has always bugged me on old Microprose's games and I felt it would make the whole scene more believable.
I hope this is the kind of C&C you guys are looking for.
I'm working on more stuff to contribute.