Mario Kart — 8 Deluxe Rom Archive.org

If your interest is strictly in digital preservation and you own a physical copy of the game:

Because the game is not "abandonware," downloading a ROM from a third-party site—even an archival one—is generally considered under current law, even if you already own a physical copy. mario kart 8 deluxe rom archive.org

Many believe that downloading a game they own on physical media is legal. However, in the United States, circumventing technological measures (like the encryption on a Nintendo Switch card) to create a copy, or downloading a copy from an unauthorized source, is not protected under "fair use" laws, according to Digital Millennium Copyright Act (DMCA) guidelines. 3. Safety Risks If your interest is strictly in digital preservation