NSP stands for . These are the digital files identical to what you download directly from the Nintendo eShop. Unlike XCI (cartridge dumps), NSP files allow for easier installation of updates and DLC without needing to merge partitions.
For the average gamer, Dead or Alive Xtreme 3 Scarlet is a shallow grind—you play volleyball to earn money to buy swimsuits to watch cinematic cutscenes. However, for the collector and Switch modder searching for the "NSP UPD Exclusive," it represents something else: dead or alive xtreme 3 scarlet switch nsp upd exclusive