I think that sprite needs a bit more work, here's the stuff that stands out to me:
The belly hole looks odd.
Conning tower looks misplaced, too far forward/no volume?
Tail appears flat and sticks out too far, edges are sloppy imo.
Engines don't appear to connect to a power plant.
Sides appear to have sheer walls, looks flat.
The area between the two rear turrets, lines lead nowhere, asymmetry in descending diagonals, despite the ship being symmetrical.
Ship appears to lack body in general.
I'm at work, so I unfortunately can't mark the areas visually. Maybe post it in the sprite judgement thread? They're probably more constructive than me, besides, I'm not a sprite artist.
EDIT: scribbled
