By checking out and compiling the iOS version of the GameCube Dolphin emulator, I got this emulator running natively on Vision Pro.
This makes it possible to play GameCube games with just a DualSense controller and the Vision Pro!
The quality is often higher than the original since Dolphin supports higher rendering resolutions and improved texture filtering.
iOS version of the Dolphin emulator:
GitHub project with build instructions:
Original Dolphin Emulator: