hmmm. im not feeling the render at all to be honest. seems...a bit blurry ?! love the background tho. awesome job. the render just doesnt stand out to me great job though.
I think the compo could use some work, colors too fo sho. The joker isnt green... Try sharpening a bit, throwing a gradient map on with with the layer style on like saturation or something, and make the stock bigger.