Well, the best way to determine if such a store would be a success is to look around at what's already in your community. Is there a niche that this gaming store will fill? Is there a large enough consumer population for it? Should you branch out into other types of gaming? Are there already franchise holders in the area that would be competition?
What can your store offer that Gamestop cannot? What can your selection offer that Wal-mart cannot? What will your price range be? Will you have better deals? Will your prices be the same? More, if you have to factor in import charges and exchange rates? What will your stock have? Domestic releases? Indy developers? Import titles? Will you hold events?
Another thing is the consumer market. Will it be viable? The main reason for the failure of comic stores in Gettysburg is because the consumer market is too small to compete with our crazy property taxes. Comic stores in other areas change hands frequently, and it's not unheard of for startups to close quickly. The consumer market is too small in some areas. Places like Harrisburg, Chambersburg, Mechanicsburg, York, and Lancaster can support one or two comic stores, as they have a larger consumer market. Gettysburg doesn't have a large consumer market. When your local comic store owner can identify you by name and count on one hand the number of customers each day (or week, or month), then the market is too small to be viable.
What you could consider doing is branching out to tap into other markets. Include tabletop gaming supplies and card gaming supplies. Have a room for tournaments. Put in board games, such as Settlers of Catan and HeroQuest. Make the store be all things gaming. Dice, game books, source books, cards, mats, miniatures, sculpting supplies for miniatures (and a display case for people who make customs), painting, throw in modeling supplies for dioramas, have room for people to play, schedule tournaments and events, along with the usual assortment of video games and paraphernalia.
The more consumer markets you can tap into, the better chance at success you'll have.