As the picture seems to be in a wooded glade I don't mind the shadows as much, or the darkness of the composition. I think there's more than enough contrast difference to make the circle pop out as the main point of interest. However, I really don't like the trees on the right. While they do add some context, the shadows and background do a better, and less distracting, job of it. I think the image would have been stronger with a different crop and/or a different horizontal angle to the wall to eliminate the trees. And while the vertical angle is fine, I think a shot from a lower height angling up would have added a bit of drama.
