SceneKit on visionOS works flawlessly.
My only complaint is that Apple doesn’t have an official hardware game controller, so any game utilizing a keyboard, MFI, or GCVirtualController cannot be easily ported to visionOS.
For example, say you have a FPS:
macOS could use the keyboard,
Apple TV can use the remote as a controller,
and iOS and iPadOS can use the GCVirtualController.
visionOS, however, cannot use a dPad without hardware, so shipping the game using gesture controls is incredibly frustrating.
I tried using spatial swipes and pinches and had to put all visionOS game development on hold.
What would make visionOS ports super simple would be to add some kind of remote or controller packaged with Vision Pro 2.
Otherwise, you have to use tap games...