I'll start by saying the exterior looks really good, although it's plain. Add some color or more little structures to the top/bottom surfaces and it would look awesome.
The interior could use a lot of work though. The walls of rooms are built out of 1x1 bricks (very spammy and unattractive), the halls are wide open and comprised entirely of ninety degree angles, there's not much color, etc.
It's not a bad start at all, better than any spaceship I've ever built for sure. It's just really bland and lacks detail, but that could be fixed if you gave the decor another go.
