An is the official digital file format used by Nintendo for games distributed via the eShop.
The standard file format for digital Nintendo Switch games is (Nintendo Submission Package). This format is the official container used by Nintendo to distribute games through the retail eShop channel. Base Game Size: Approximately 1.1 GB to 1.5 GB. Format: Digital eShop releases use the .nsp file extension. lost castle switch nsp update eshop
If automatic updates are off or you want to check immediately: An is the official digital file format used
This guide explains updating a Lost Castle NSP (game file) to the latest official Nintendo eShop version for Nintendo Switch. It assumes you own the game and are updating for personal use. It covers how NSP updates work, how to locate and apply official update NSPs or Delta patches, and best practices to keep your game current and stable. Base Game Size: Approximately 1
Modded consoles use installers like Tinfoil or DBI to apply update NSPs. Finding Updates on the Nintendo eShop
Official Nintendo documentation explicitly states that “the use of an unauthorised device or software that enables technical modification of the Nintendo console or software may render this game unplayable”.