Acclaim (+ LJN) is a 3rd party publisher for the original Nintendo who seemed to have an affinity for showcasing new and upcoming games at CES in the form of mock up box art.  I would attribute this to the fact that Acclaim opted to manufacture their own boxes, manuals and carts rather than pay Nintendo the privilege of doing it for them.  It was likely easy and relatively low cost for them to run a small print of boxes for their booths at CES and other electronic expos.  A small amount of these ‘prototype’ boxes have survived through the years and have made their way into collector’s hands.  While some of their covers appear identical (or have one or two small revisions) to the retail release, the main tell of these boxes are the blank backs.  The most interesting ones, however, are radically different than the final release and can offer insight into how the original box art concept changes over time and becomes the final product that winds up on store shelves.  Right now, there are a few of those boxes up on ebay, for a rather high BIN (though there is a best offer option)
