I really like this. Have you considered two things? First, having the substrate even at the front. I think it would make the "mountain" look more imposing, in a good way. Second, I think the mountain could be taller, both to fill up the height of the tank (like 2/3 the way to the top), plus it wouldn't be the same size as the left rock (don't know if you removed it or not). Just my opinion but I really like this a lot.