The official webpage for Marvelous Games' Rune Factory: Guardians of Azuma has this passage:
Assuming this was not some kind of typo, this seems to be new information since the switch 2 game cards are listed as only compatible with the switch 2 on Nintendo's website. So it would seem that either all switch 2 game cards could be read from switch 1, or there is a subset of game cards specifically designed to be read by both.
source: https://marvelousgames.com/news/rune-factory-guardians-of-azuma-nintendo-switch-2-faqWhat is the physical "Nintendo Switch 2 Edition"?
The Nintendo Switch 2 Edition is a red 64GB game card that includes, in full, the Nintendo Switch game and the Upgrade Pack.
There’s no need to download the full game: simply insert the card into either a Nintendo Switch or Nintendo Switch 2 console, and the correct version will launch automatically.
Assuming this was not some kind of typo, this seems to be new information since the switch 2 game cards are listed as only compatible with the switch 2 on Nintendo's website. So it would seem that either all switch 2 game cards could be read from switch 1, or there is a subset of game cards specifically designed to be read by both.











