Bummer no one commented, I like it though!
There are some open spaces, but with proper planting, I think it will look nice. I guess might want a taller rock somewhere? The more I look at it the more I realize there's not really a definitive focal point, I suppose the cave looking part that's nearly dead-center. If that's the plan, then you might want to move it more off center. And the rocks on the front right will get lost in plants unless you have really low ground cover, you might consider raising them out of the soil a bit.
What are the planting options?