Well, as a whole, it looks very cartoony. If that's the look you're going for, I'd say right on. The stairs up to the middle platform seem to have a weird rendering issue. Would be good to bevel some of the hard edges if you haven't.

Where things touch the ground, it'd help if the ground had some sort of reaction, whether it be an upheaval or a texture change or something. Where buildings and ground meet is very sharp for the most part.

The water could use some reflection and some transparancy.

Keep it up!