Kind of trivial, but:
- In the area with the wood plank floors, the planks don't end cleanly with some of the edges (looks weird having half a plank up against grass)
- In the middle high area with the fence thing, the top edge of the texture is a red wood, but you have a green wood along the top.
I don't know how much you're willing to change the map, but it would be nice if the walls and ground outside were made to look a little more natural. I'm also not a fan of the same wood texture being used almost everywhere in the base.