You cannot move or copy your save files to a microSD card for manual backup.
Super Mario Galaxy is a fantastic game, and I'm happy to help. Since it's a popular title, I'll provide you with some general information and tips related to save files. mario galaxy switch save file
If you're looking to transfer your save file to a different Switch console, you can use the following method: You cannot move or copy your save files
If you’ve already beaten Super Mario Galaxy on Wii or just want to skip straight to the post-game content (like playing as Luigi or tackling the Grand Finale Galaxy), using a pre-made save file on Switch can be a huge help. Here’s what you should know: If you're looking to transfer your save file
✅ Get a save file if: You’ve already 100%’d the game elsewhere and want Luigi or final challenges quickly. ❌ Skip if: This is your first playthrough, or you’re not comfortable with homebrew (risk of Switch ban).