runouw.com

If Mario isn't in the very center of the screen, then the sound only plays in one ear, depending on the side Mario's on. It gets pretty annoying and I'm guessing that it's fixable, and I don't recall ever having this little bug before Runouw updated the game with the new level designer. Also, if you go down a pipe as Luigi, the sound duplicates.

It's not necessarily a bug, it's called Stereo sound. But yes, it is a little annoying. If it bugs you that much, go find a website that has an older version of Super Mario 63 and see if that version has Stereo sound. There's plenty out there.

That's too bad, now I can't use warp pipes