I'm not a big fan of the huge character montage. It's just too busy. I'd cut down on the number of characters you have in there, maybe focus on your favorite games / time period or something.
Even if you ignore the last statement (which is cool, it's your marquee after all, if you dig it - that's all that matters), Space invaders looks completely out of place compared to everything else.
Before you print, find out how much of your marquee is going to be covered by the retainer or whatever you are using to mount it, and resize it to fit. I think it will look much better if your artwork stretches to max, and you have to cut off a small portion of artwork, rather than have the black border. Either that, or design a more integrated border that protects your character art, while allowing you some wiggle room for trimming.