Yes! RetroArch lets you swap the A and B buttons for just one game without affecting any of your other games.

Here's how:

1. Launch the game you want to change.

2. Open the RetroArch Quick Menu (usually F1 on a keyboard or your configured controller hotkey).

3. Go to Controls → Port 1 Controls.

4. Find the A and B button assignments and swap their functions.

5. Go back to Controls → Manage Remap Files.

6. Select Save Game Remap File.

That's it! RetroArch will remember your custom button layout and automatically load it whenever you launch that particular game.

Important: Make sure you select Save Game Remap File, NOT Save Core Remap File. Saving a core remap would change the controls for every game using that emulator core.

Your other games will keep their original controls, and your RetroArch menu buttons won't be affected.

I think there is a guide to this somewhere on the website. Let me see if I can find a link and get back to you!