I don't like the over exposed and purple sky, it is just too unnatural. Your composition is good and it does show desolation. I think the purple sky will hurt your scores though.
I'm not sure if I like what you've done to the clouds, they seem very purple and over processed, while the ruin is quite simply processed - feels like a bit of a mismatch. I like the ruin and the ivy but the rest of the photo isn't quite as good. And the horizon also needs to be straightned.
Arrgh what have you done to the sky and this black/grey blob in the bottom corner. Feels like you mashed this in photoshop. The greens and the main ruin look Ok but the backgrounds have been killed. I'm guessing you started with a ruin which was under exposed and tried to compensate in ps.