There really needs to be more decent melee maps on the hive, it's a dying genre sadly...
What I suggest to you is to use Dungeon trees on outland, looks alot better then the outland ones imho... Also it's hard to place my finger on it but something looks rather odd about the tile variation, and it seems that Red and Blue have slight advantages like being able to cut into the tree wall to the expansion quicker.
Other then that though I like it, 4/5.