Hey Mike,
That looks pretty good. It's nice seeing all the phases. The lower left one which looks like it's silhouetting some flowers on a hill side, may not come across real well on the web, being small I had to look for a second to figure it out. But when printed larger, that will be really cool and much more readily discerned. I think that's a great touch to this.
As a thought....
I wonder if that lower left corner where I am assuming is a hillside, what if in that corner, you just ever so softly went and lightened it. I am thinking so soft and subtle with just a hint of detail or outlining, but just enough to let it anchor that corner? Just an idea, not sure if it would even look good. But a thought for you.
Jim