Part of the problem is the Jones Act, also known as the Merchant Marine Act of 1920. It is profoundly dry reading, but its profundity to Puerto Rican retailers is hard to understate. The Jones Act essentially requires that all U.S. territories, such as Guam and Puerto Rico, only receive trade from the mainland with U.S.-built ships, entirely U.S. crew, and only to U.S.-owned barges. Even in the best situation, this massively increases the cost to get products into Puerto Rico, but the lack of usable and safe barges adds time as a factor as well. Shipments can queue for weeks at a time, which stops imperative videogame releases from reaching store shelves until well after launch.
A fascinating look at the game retail industry and how it interacted with laws in Puerto Rico.