The model looks OK, but the Textures are dodgy IMO. The whole thing looks too regular and boring (and yes, I know you think that anyone designing the ship would want to use a standard size of armour plating, and I agree - but this is a game, where looks are more important than reality) and the big thick black lines and monotonous grey makes the whole thing look cartoony.
If those lines have been drawn on as vectors, I'd suggest you edit down the wifth by a few pixels. If they're rasters (Which is far more likely - vectors can be a pain to work with) well, you may be stuck with them.
A few hints:
1 - Vary the size, shape and and especially colour and brightness of your plates. It will make your armour look 100% more interesting straight away.
2 - Texture your armoured plates after you draw the lines on - at the moment it's really obvious that you used a textired fill and then drew lines on top - the textures continue through the plates, which completely throwes any chance the ship will have of looking built rather than modelled and textured. When I texture my plates, if I use a fill at all it's only over a single plate space, and then I generally go around the edges with a textured airbrush to try to segregate the texture on this plate from those around it. It also helps to vary up the colours and brightnesses a bit. Also, if you're putting your texture on after the line, you can use a low tolerance fill or magic wand to differentiate each plate to vary the colour up a bit - as it is now you're probably going to have to box select each plate to change the colours (and I fear it'll make it look even more textured rather than built if you have contiguous patterning between plates with different brightnesses).
3 - Use thinner, slightly brighter lines. Single pixel dark grey lines between armour looks a lot better and less cartoony than big thick black ones.
4 - Bevel your plates. A lot of people may disagree with me on this one, but I think it makes them look a lot better. It's not for every ship, granted, but in some cases it looks really good, especially in conjunction with variable size/shape plates.
