Pretty neat concept you got and it's fairly well rendered but there's still a lot of work that could be done in my opinion.
I kind of think the two styles clash a bit, the large pixel people and the regular sized hills and clouds. One way you could possibly tie this in better would be to make the details of the hills with this large pixel brush/size and even shade the clouds with large blocks of color. I'm not really sure how you will want to do this but I think it deserves some attention.
Secondly as VictorR mentioned the colors could use some work. I made an edit of some stuff I think you could do with the piece to bring more life into it. (I realize my some of my colors came out similar to VictorR's without looking at his piece. It's just how my colors turn out usually).
I hope this can be of some use.
