It's not too bad actually.
Personally, seeing as how you're building it out of Cube's, I'd suggest making cubes into the water as well. So it's not just sat on top of a large flat cube. That way the land looks more realistic and less placed on a block.
Your colour scheme is a bit odd with the building on top, but I like the building itself though, if it has a couple too many ramps for my likings.
Overall, it's pretty good. Could just use some little edits here and there, and most of the things are just things that I personally aren't quite sure with. Good work.
