Downloading Nintendo Switch games in format from unauthorized sources is a complex topic that involves significant security risks and legal considerations.
Yes, public libraries lend video games. Many major city libraries (including in Spain and Latin America) have Switch games. You borrow the cartridge for free, install any updates, play, and return it. Cost: $0.
NSP (Nintendo Submission Package) files are a type of file format used by Nintendo to distribute and install games on the Switch console. NSP files contain the game data, including the executable code, assets, and metadata, which are used to install and play the game on the Switch.