hmmm, I find this piece rather stunning in its simplicity and looks finished and polished too me :/... I love it.
Maybe because it feels and reads like a Japanese painting I don't mind the simple pixelling and seems a delibarate design choice.
Hmm, remind me some NES game scene, Mb Werewolf: The Last Warrior a little)
Dude, i think this isnt a finished work. Make more details in sky, and the grass. And about the colors, if the tree and grass are dark pallete (black and gray) use this in sky too.
Looks like the pixel version of a comic panel, colors look perfect to me.