They aren't actually in the store (unless something has changed big time). The are probably just in the catalog, and maybe there is a little info sign near the pool tables and stuff.
When I worked at Service Merchandise we had a lot of big crap like that. which we soold, but didn't actually have any of. (Swingsets, big pools, pool tables, etc). If the person bought one, then it got shipped to them from the factory that made em in the first place. (And in the K-Mart case, those games are coming from that mega-overpriced reseller Betson Interprises).