Nice lighting on the last one! Keep it up! Try to add some more elements on the empty spaces in the sides of the city. You can use abstract brushstrokes to suggest trees, rocks, etc and see what works for you.
And something else I noticed is, the circular-kind of shape of the left mountain is a little weird, it gets a little distracting there. Try to simplify it, or move it around, see if it fits anywhere else.