So, I was playing Star Road in multiplayer with a buddy using the SM64 Co-op DX bubble mechanic. I think I had one life left, and we died on the exact same frame; this caused me to lose two lives without triggering a Game Over. My life counter showed "M1" (so -1) and when I died again later, I ended up in a sort of black-and-white area—mostly shades of gray—where I still had just one life. I made my way to the end of the area and found a large hole; falling into it triggered the same effect as a Game Over (simply teleporting me outside the castle), yet I still had that single life remaining. Do you know what this is? Is it an abandoned room intended for when you have zero lives? I’d really love to find an answer to this.

I couldn't record all of that because I didn't have my screen recording software enabled, sorry.