Ehhh... Big disappointment. Many bugs in graphics, transparent parts in rocks or grasses. Really maybe they look beautiful from this page, where all are prepared and put into one pretty scene. But parts are chaotic and even not matching sometimes.
Grounds cannot be joined because when you try to put one over another they do not match by grass or by ground rocks. I think that it should be fixed, because current version is hard material to work with. I'm quite experienced designer, and I see many shortcomings that I will have to fix before I will start working with that. As an artist author is quite good, I see some problems but generally graphics are good. But you know, details like exported graphics etc. they are not so good.
PS: All that bugs are not visible on your scene graphics presented here on this page.