okay.. I will start with the rocks, the grass ..
regarding the trees. could you to make sure that the tiles remain in the air? To make a tree in 3D [(and not using wall events as not to overload the loading of maps)] I need you, through the heightmaps (or new terrain tag or something similar), can be made to float a tile. Could you do it?
If you can not .. Also the bridges could not be done :/