@Thanks, I am trying to improve. It's Moon rising instead of Sun.

@Consalvo Lines of the trees and mountains have different brightness. Each of them, there are 3 rows of mountains too. And clouds above, which fade, they deceive the eyes. I understand that some pixelartists strictly follow limited palette, I am using 24bit palette very often.

it's preloading title for the game.

I like it! However, I feel like the low sat seems off for the time of year that I assume the scene is taking place in. To me, it looks as if it is autumn. I feel like the trees and changing of the leaves should make it a deeper/richer color. But most certainly like Mac has put it the shift from darker in the foreground to lighter in the back does give it some depth. It looks excellent though!

Hum 136 colors, what happend here? 

Wise decision to make backgrounds lighter, it will help with giving the effect of distance. Be careful not to over do it as it can result in a fog effect instead.