The buildings look good. However I'm not sure about the wall. Firstly there are some great big holes in their defences! I assume that was meant and will be filled in later. However my concern is a little different to that. Walls are usually built pretty early in a cities life and usually only contain the core of the city. They are expensive and difficult to build. Once built, the citizens all want to live inside. Therefore I would expect the city wall to encompass a smaller area than you have, and for the are inside to be densely populated, with a sprawl of smaller buildings (after all, those outside the wall are poorer) outside.

I guess everyone has to have a bugbear (RobA with his rivers and RPMiller with his toilets), and I suppose this could be mine. There have been a few examples recently of city maps with truly enormous walls - almost as if the generous government has decided to build some walls that give the city room to grow into. I doubt this was ever the case as walls are expensive, and the larger the wall, the more area you have to patrol. On the other hand I don't know (I am not an historian) for sure and I'll be happy to be proved wrong if someone can find an example.