Nintendo removes demos constantly. The Internet Archive hosts "Lost" demo NSPs. For example, the Dragon Quest XI S demo (which had a unique save transfer) or Project Octopath Traveler demo are considered "best in class" for preservationists.
: On any item page, look for the "DOWNLOAD OPTIONS" section on the right side. Clicking "SHOW ALL" allows you to download individual files directly. internet archive nsp best
: Specialized in supplemental content, including updates and DLC for games like Bayonetta 3 , Red Dead Redemption , and Tomb Raider I-III Remastered . Nintendo removes demos constantly
Not the games themselves, but config files for homebrew shops. Red Dead Redemption
: This collection is specifically useful for finding game updates and DLC content to supplement base games.