Ah, terribly sorry about that. I'm a PixelJoint noob and honestly didn't know there was zooming. ^^;

The shading seems to be rather inconsistant, or rather, the outlines. The outlines are a darker version of the colour inside at some points, and at others, it's simply a black outline. I'd suggest you make either a black outline for everything, or a darker version of the colour outline for everything. The windows could also use some work, they look like white rectangles as opposed to actual windows. Maybe you could make them a light blue, and add some shine?

One last thing, the grass texture looks a little weird. The green is too vibrant, it contrasts with the rest of the image's darker greyer tones. Other than that, looks pretty good.