Just the front, and try to cover up publishing/development and console format information imo. You want the main illustrations to be the focal point not the corporate crap. That can look tacky if there's tons of logos everywhere.
What *I* would personally do (and though I have no real qualifications, I am an avid art lover, so I have *some* idea what I'm talking about. But this is just a suggestion, feel free to tweak or ignore)
~I would make it one large complete piece. Series can be fun, but one big piece will probably make it pop more and be a vocal point of the room. I would do a simple shape like a circle or ellipse (either with the corners of the insertes pointing off the edge or smoothed over to give it a organic contour. I think the latter would be cooler given the contrast of the hard geometric lines of the insert edges, so I'll explain how to do that when I get to it)
~Pick the inserts you actually want to use. Do you want to use all of them? One ones you think look cool? Do they look cohesive together?
~Sort them out and arrange them in some sort of gradation that you want Value (light to dark) Hue (bright to dull) by color (go by the color *predominately* featured on the insert, if it's about 50/50 it can be a transition piece) This can help with setting up your composition (so if you place a insert in a spot, think it doesn't look right. You can easily find an insert that fixes the problem you identify "This section is too dull/ the blue doesn't look good here" etc)
FIGURE OUT YOUR COMPOSITION BEFORE YOU START PUTTING THINGS IN PLACE PERMANENTLY. Put the inserts next to each other and see how they look, and just build up. This has caused me so much woe. And remember, looking good is your number one priority. All those fancy art suggestions won't do you a damn bit of good if it's not aesthetically pleasing.
Now the actuall construction. Get a piece of posterboard/cardboard/whatever as your ground. Make sure it is big enough for what you want. Cut it into the shape you want if it's not in that shape already. if you're feeling brave you could do some really cool things with the physical shape of the piece.
this step is optional but some people who like to do collages (which is what this is) like to do this. Get some sort of artist painting protection glaze (the kind that goes on paintings, not walls)You can get matte or glossy whichever you prefer. Coat the inserts both front and back with a thin layer of this. (Wait for the other side to dry and don't freak out when it curls, once you do the other side it should straighten out, and if not. You can always just put something heavy on it for a while) This makes the inserts more managable during the collage making, I recommend it as you should be getting the glaze anyways.
Put you composition together and glue the inserts onto your ground using an adhesive like rubber cement or something like that. If you treated your inserts before your shouldn't have to worry too much about wrinkling, but still be careful and make sure to smooth those puppies out and be stringent with the glue
To have smooth edges on your ground just glue the parts of the inserts that are sticking out around the edge and onto the back.
Coat everything in another layer of your glaze for extra protection let dry for a couple of days then mount it up. (This can be done by just taping some string on the back then putting it on a hook)
Protip: take it slow. There's a lot of drying going on here and you don't want to rush and mess up something that's wet because you're impatient for the result. Making a good piece of decoration will take time no matter how you decide to go about it.
