So here's some issues that you generally have with faces, you draw the eyes as one continous line, this is not necessary, it makes them look flat. If you have a line for the bottom part of the eye, make the upper one thicker, don't worry, this won't make guys look girly, that's only happens when they have long eyelashes.
Eyebrows are not rectangular caterpillars, they have a curve and usually taper off at the end. They are also too short, check the red lines on my reference to get an idea on where the eyebrows should end.
Also, when I was redrawing the face, one issue could be the doe eyed look the characters have. I normally don't draw iris' so large and even when I "fixed" the eyes the guy still looks creepy.
He also doesn't have much of a jaw, he has a clef chin but it's really skinny. Thicken it! Make it more manly! A good rule of thumb for ear placement is top of the ear lines with the eyebrows, bottom lines just under the nose.
You didn't specifically ask for anatomy advice, but it's just something I noticed. You appear to be using 3d models for poses. I'm not knocking on 3d references, they are great to understand perspective, but too many people use it without knowing how anatomy works, muscles stretch and squash depending on how the body moves and 3d models don't do this. (At least not the cheap ones) And it also doesn't help you understand how fabric folds. My advice would be take pictures of yourself to see how muscles move, use it to supplement the 3d references instead of relying on the latter alone.
I normally wouldn't go so in depth about figure drawing, but your comic is more of a serious sci fi and not cartoony, so that little extra step could sell your art more, especially since your backgrounds are drawn really well, (I do know they are also 3d models, but it's easier to get away with when it's geometric shapes) so the characters should also reflect the nice scenery.
