Just a few things...
There is a little black square on the back (on the left side of the cast) that does not quite match the rest.
"Wars" is cut off of the ESB logo on the front.
This one is really picky, but being that I really like what you have done, I think it may help...
The colors on the "Star Wars" poster seems just a little dull in comparison to the other posters used. Select that area and use your "Color Balance" found in your "Image / Adjustments" (assuming you are using Photoshop).
I hope that helps! Great work!!!