I'd first go with what is the purpose of the ship,  what form of engine would it have,  It seems to have an intake vent used in jet engines.  From the looks it seems you would use it in outer space, and for use in landings where there is an atmosphere.  The top tail fin looks to large, the large rear door would make me think it is made to hold  a large amount of cargo,  possibly move the cargo door to the side where it is flat and make the rear smoother, more rounded.  The enlarged nose of the ship makes me think of an insect,  I'd like it more if it did not get narrower. Also I'd think it needs some type of identification letters and or numbers.  I'm actually new at the 3D stuff, I've been working with a 3D avatar used with an AI chat bot and I'd like to get a higher poly count wire mesh into the character.  I'd say you put a lot of work into this, hope I haven't been to critical, take it for what it's worth to you and I wish you luck with your project.

Carl