Lacking inspiration or time to finish it?
In fact, lacking global direction, I kind of lost my compass doing it, playing with perspective was the main goal but I didn't thought of what to do after the perspective was set. I don't know where I can place some lightsources, or what texture I want to paint or ... well there are several possibilities but none really satisfies me, so I'm stuck.
The only thing I still have is some palette ideas...