You know - I considered whether to brighten it up a bit more, but then I realized that i am trying to make this as realistic as possible. Bearing in mind that the moon is the primary source of light in this image, I didn't want to bring up the ambient too much as it would also take away from the moon's reflection. I will be cranking out some more of these as well, so some tweaking is going to happen.
You have succeeded at something very difficult in this: while it is very dark, all the elements in this landscape are discernable, like visions coming out of the darkness. The lithing is used very well. A challenging and excellent work. :)