It's very odd, the metalic features lines are very irregular, smoothing them out would make it flow better.
The way you shaded the visor is very different from the rest of the set, perhaps making it metalic also would help?
I feel there should either be more black or more grey in the background, it's kind of random throughout the whole set.
This isn't your best work and I think you can do a lot better.
7/10.
The colour scheme is nice and the whole idea is pretty cool.