To be honest, it kinda sucks. With the zenkou tiles you should be able to make a much better level. Also try using perspective or atleast realistic roofs, notting personal but I hate it when people go oh lets make a weird ass roof that so shows how great my skill is (well it can.. if atleast the perspective is right >.> but thats almost never the case)
Improve the perspective
Use some more tiles and improve detail and it will look very nice.
You're edges water/land and grass/sand might also be more creative. Try just pulling out some parts and making them swirly or a bit more complicated, this will distract people from the fact that other lines might be quite straight.