Tiles

[Fool]

Your stones are very clean and well defined and I think you ought to bring everything else to the same level of definition. Right now tree a bit off that level both the trunk and the crown. I'd get darkest shade on the tree a bit lighter and less saturated. As to foliage, if you work from back to the top you may get better control over it. Here is a rough example. Leaves shapes up to you, perhaps.

[Reo]

I don't know if its just me,but the composition of thoose two branches has been bugging me since the beginning.
Maybe move one of the branches a bit up(sloppy edit):
but maybe its just me

[Opacus]

Yes Reo you're right. I will fix that soon

Here's an update, refining the leaves.
It's not a major one, just showing, that now I have internet again, I am still working on this and I will finish it.