That's pretty detailed...I love the grass on the roof. The texture of the wood also feels pretty realistic. It's a little too bright at some parts, but that isn't a really big deal :)
P/s: Just saying, grass should grow upwards no matter the surface :P they always follow where the light is.
Ohh yeah, i had an mind set like they would grow on an angle, like i had seen pictures of it happening but just goggles and couldnt see any good ones :D you are right it doesnt :D