This is beautiful and really unique! I love the dappled light on the nearest building and trees. Thanks for sharing the process too! I'm a Photoshop noob, so it helps me to see the different approaches to PS painting.
My main two problems with this pieces is the distribution of detail and obvious attention between the fore ground, mid ground and background. And the biggest problem I have is the perspective, which is confusing. It's great that you can show off the process and show off your ability to paint, but you should start with at least a point of reference in terms of perspective. An example of this is the mid-ground buildings which have some parts being round, and some being obviously flat. If I was to convert that into real 3d, the rounder parts would literaly hang downwards.
The amount of detail and attention you put into the foreground image is great, but the midground seems hastily put together, and the background seems like to just turn into blobs and spires that also, due to lack of understandable perspective, look strange.
In conclusion, great use of color pallets, good architectural design, but your lack of perspective and lack of intimate attention to 70% of the image, is too obvious.
Perspective is not one of my strong points but I do make an effort to make it right more or less. The perspective in this piece is somewhere between bird's eye view and ground view. I guess it's an elevated front view. It seems I haven't made it understandable enough though. The two structures in the middle are rounded while the long extensions were meant to be flat and since it's parallel to the viewer they will look flat. I'll work more on perspective.
I'm really into achieving a sense of distance so I exaggerate it with varying contrast. For example the foreground is much sharper, more saturated and darker than the mid and background. I did put a lot of effort and time on detailing the middle ground but they're not as sharp as the foreground so they might appear "hastily put together". There won't be details in the background too again because I want to emphasize the sense of distance.
I need to work on gradation to achieve depth rather than stark contrast between fore, mid and background so thanks for pointing that out. I'll include that on my "to practice" list.