With those installed, you’ll have 16 classic Sonic adventures (4 main + 12 Game Gear) plus Amy Rose – making the Switch version one of the most complete retro compilations available.
The NSP UPDATE DLC for Sonic Origins Plus on the Switch is a significant update that adds even more content to the game. NSP stands for "Nintendo eShop" and refers to the update package that can be downloaded from the Nintendo eShop. Sonic Origins Plus Switch NSP UPDATE DLC