Okay good things first: the ship looks cool and the line-art is decent overall, the best thing is, like swapbrain said, the palette - it's really cool and easy on the eyes!

But, to put it bluntly I first thought this was a WIP rather than "
cartoony-style" and it comes across minimalistic. (well, that's my opinion! :x)
Even if you make more detailed texture you can keep the animeish look you're going for, I think SwapBrain made a great edit to show you that rocks for example aren't just round objects with ligh that shines on them...
rocks have edges and all that...
Same goes for the wood of the ship, I'd really look at wood texture in real life or even games, it helps.
If you don't agree with all that and even if you do, I think some AA would be necessary

Peace.