The tree trunks look a little off..it's slightly curved on the left side but totally straight on the right side. And the trunk shouldnt get thicker as it goes up. Maybe.
The tile above the little ponds has different color grass and is missing a part of the lighter green grass that seperates the dirt from the dark grass.
The water in the top right corner, the edge of the land seems to end when the top of the tree starts. Maybe it curves down-right behind the tree and we cant see it?
Still, it doesn't take away from the awesomeness of this screen.