Awesome work on this, man. Great use of color and amazing sense of depth and distance. The colors are perfect; the way you desaturate the blue with orange as oppose to grey to get that fade out effect is beautiful and provides a great sense of harmony with the orange glow of the sky, which in turn brings it back with the smooth transition back to blue. The shapes you use here for the trees are very interesting and pull it out of reality a bit which is great and compliments the shapes of the city off in the distance. The trees also do a wonderful job in framing the picture and focusing attention slightly to the left giving the sort of effect that we are looking in the same direction as the dude on the bench. Back to the sky, those clouds are great in the way that they are not overpowering, and very lightly done, they're the perfect opacity and thickness to just break up the sky and communicate the difference between ground and sky without drawing any attention to themselves and overpowering or distracting the other more interesting areas of the piece.
However the guy on the bench probably could be depicted a bit better, while his placement is great since the silhouette breaks up the image and provides guidance to the city, I think right now under close scrutiny his body seems to be too thin at the waist area and the way he's so close to the bench's support plank, it appears he has three arms; also his left leg looks very thick compared to his right one.
The moon's placement could probably be better as well, it could be just me, but right now the way it appears to be in the horizontal middle really pulls my eye too it as I go across the image which I feel shouldn't be the case as the skyline of the city is so much more interesting. I think it could benefit from being made lighter, being made closer to the orange of the sky, being moved to the left - any combination of the preceding or even being omitted entirely.
But those are small gripes, fantastic job on this.