Your buildings look a whole lot better now you have reoriented them

I have to agree with Jo about the composition, though. Sorry!

On a different point - Everything seems to be just a tad pixelated. You might consider working at twice the size and then reducing the output by 50% before uploading. That brings antialiasing into play, and will give you a lot more scope for adding details.

An example of what I mean...

The GIMP file for Nexus in my own entry is 6000 px across from side to side, but by the time I upload the map its only 3000 px across. There are all kinds of mistakes in the original - tiny ones that disappear when the city is scaled down that way