You've got an impressive collection of sci-fi, post-apocalyptic terrain. Perhaps you need some large building rubble mounds that function as elevated terrain. Hills are interesting strategically because they provide an advantage, but they can also hide an enemy approaching from the opposite side. Mutant trees would also be interesting, and you make awesome "natural" pieces.
I clicked the like button the moment I saw the cracked tarmac. Looks awesome. And where did you get the idea for that freakish piano music in the glamour shots? Really set the right mood in an instant.
I'm always amazed of your overgrowth. It looks so chaotic and in that so natural, great. I wonder what your real garden looks like. Straight lines with perfect mawn grass and dwarfs watching over it or are you the shame of the neighbourhood?
My dear, I see the mark of a true craftsman in you at about 8:10- never clean that work mat, you never know when you might need to scrape up some character to a piece!