Very nice rendering and technique in general, but I think you have to pay more attention to the material nature of things.
The grass in the top tileset looks more like some goopy slime, because of the way it is separated from the dirt bits. I would not say draw every strand of grass, but it would look a lot more like grass if you had some strands showing here and there (like you have at that tombstone looking thing)
Also the edge of the river/lake looks VERY artificial with a nice trim a single stone wide. I would say vary the sizes of the stones a bit more, make it reach into the grass more in places and so on.
The bushes or high grass (I assume that's what they are) look weird and do not work for me. It looks as if someone took it from somewhere else and just put it there.
I think that in general is my main crit with this. Most things do not seem like they are organically connected. The trees, the way the grass borders on the dirt, the bushy things, they all look like setpieces places there to form the whole, not like they organically grew there, if that makes any sense.