The thing looks like it would rip apart, try to kill some of those 90 degree angles. Add more of a transition from the wings to the body as 90 degree intersections are not great for flying things. Most ships are star or triangle shaped, this is not a rule it just looks nice most of the time. Consider making the body come to a point rather than a blunt surface, it will look more sleek. Try so add some shapes rather than blocked in parts with beveled edges and see if not using inner outlines works better. I would also consider lining the guns up by length. If your windshield is that shape it would actually have 6 side, your are currently only showing 4 of them. Everything looks the same height you might make them more rounded they kind of look like beveled buttons placed ontop of eachother. The guns could be shaded like tubes rather than flap strips of material. I would advise thinking of how these mechaincal components work and adding details based on that, it's fine if somebody doesn't uderstand a part compleatly.