This is along the lines of what I wanted to say. Going from the main screenshot, there's a lot of low-hanging fruit (in addition to what you said) that could be done programmatically like making the ground tiles look non-uniform or adding some "noise" to the land/water boundaries. Even some decals such as rocks or flowers on the ground would do wonders. The point is that there is big-bang-for-the-buck things that game developers can do with existing assets and I feel this may have been missed in the discussion.