NSP stands for Nintendo Switch Package, which is a file format used for distributing and installing games and other software on the Nintendo Switch console. An NSP update typically refers to an update package for a game distributed in NSP format.

While the technical process of obtaining and installing these files is well-documented in the homebrew community, it operates in a legal gray area and carries significant risks.

If such a file existed (and similar files certainly do exist on torrent sites and private forums), it would be:

Moreover, even if installed on a hacked Switch, the game’s online features would likely be disabled or lead to a console ban from Nintendo’s servers.