What are you trying to do? What purpose is the model meant to serve, what aesthetic goal is it supposed to fulfill? It's difficult to know if something works unless you know what it's for. If you're doing this as a learning exercise, then what do you hope to learn how to do - or what was your inspiration for taking this on?
Without a goal, you'll get subjective comments pulling you in possibly contradictory directions.
(Did you do a planning sketch before starting by the way? If nothing else, it seems like you're trying to make some kind of spaceship, but the composition seems like it's derived from shapes at-hand rather than made to fit a master plan, which returns us to my original question... )
Edit: And then while I was writing this, your posted the second part. So this is for a poster? Tell us more about this poster!
So some background on this, this is meant to be part of a project I'm doing in Unity (and other platforms). This project takes place in a larger world/planet (fictional) where many nation-states exist, some more powerful than others. There's the inhabited areas then the uninhabitable zones/Narkh (Hell) sectors, where people have ventured into them, but haven't come back. All sorts of weird stuff occasionally wanders out. It starts off when a small mining-centric nation on the border of these zones detects strange signals coming out of the zone.
This particular part centers around a squadron of aircraft sent into an uninhabitable zone/area of the world (fictional that I've created) to investigate the source of strange signals. The squad is composed of fairly outdated tech (for the time that the universe I've created is set in. It's still fairy advanced by real world standards). They find the source of the signal and are then dragged into a dogfight against this particular aircraft that I posted pictures of.
The aircraft is an unmanned, semi-intelligent, combat drone. Its technology is much more advanced than just about most aircraft tech available to most nations. It combines the world's tech with extra-dimensional/other-wordly technology to achieve more maneuverability. It doesn't use ailerons, for example, but instead uses a technology that has no mechanical alteration of the wing.
Primary armament is a set of 4 energy cannons and the ability to fire an assortment of guided mass-drivers out of two front mounted launch tubes.
The aircraft is also built with stealth capabilities in mind, but also to be mass produceable. Aesthetically, I hope to capture something that looks stealthy and futuristic. I did indeed make a sketch before modeling, of which only 50% I actually ended up keeping while modeling. It's based partly on the Dark Eldar Razorwing Jetfighter, the F-117 Nighthawk, and on UCAV drones being floated around.
Sorry I didn't post this earlier. I'm a little off kilter because of an injury I sustained. Let me know if anyone has more questions.