This is what you had when i opened it:
You used a lot of the darker evergreen set, not really my style because you had to rev up those lighting multipliers to compensate, but hey, you do you.
I replaced that bright white evrock texture with the tundra rock texture, the real dark one.
It came off a lil green so i neutralised it by dropping out some green light from the ambient light, i think
I also lowered the shadow colour and replaced it with more ambient, too, and i roatated the sun direction a little,
And this is what i came up with, it's (the tundra texture) not really setup with the rest but it's a lot more easy on the eye in my opinion, and a lil more pop in my opinion too.
Hope you can get something out of this.