I think that border looks really ugly,you should remove it...
Also,the extracting of the scan looks a bit messy on some parts,like outlines are missing,maybe you should also work a little more on that ^^
The mountains look nice,except for the left part where they look blurry and kinda smudged like a mist?not sure if you intended it to be like that...also,the petals need some highlights,and that pinkish glow looks kinda strange...
Also,isn't this a daylight wall?How come the moon is on the sky?

The grass looks nice,I like the shadow part on it...maybe you should work on the variety of the grass,but nvm,it looks nice this way too^^

Keep it up,you'll do better next time