Rate and CC please!

Well first of all, it's hard to tell if it's done. But if it is, you've got a lot to work on.

Start off with shading the picture. Otherwise, it will look bland and dull. You also need to clean up your lines, and make them always 1x1 pixel lines.

I really can't tell you much more because I am NOT a pixeler, but I hope I helped you nonetheless.

Good point. I can't really shade that well... But I'll try.

For landscapes you might want to make the black line the color of what it's surrounding

why is the sun shaded?

I don't think it is.

Sort out your screen contrast or copy and paste into paint.
You'll find it is

yea it is

Advice: You need some shading. Otherwise its a very simple-looking picture. I like the idea though, and if you shade it, it will look great