Vegetation and Tiles. Youd didn't used the grassy dirt tile, you could use it between the grass and the dirt path.
About the vegetation, you only used one grass model, and one kind of tree, more variation (hollow stumps, bushes, other kinds of trees, maybe some clusters of rocks and mushrooms) will surely improve the realism of your terrain a lot.
Time for mentioning the good part!
Yes, it is good, there aren't much flaws on the terrains (the only ones is the weird way that the terrain ends, the variation and the fog).
Keep terraining!