I have a pretty clear memory of playing a really screwed-up version of SM64. There was a snow world that was just a single strip of ice, with a wall on the right and a bottomless pit on the left. I jumped into the bottomless pit, and then I got kicked out of the painting and lost one or two health points. When I lost all my health points, it went to a screen of Mario's head spinning, saying, in a Barney-esque voice, "Ohohoho! Game over!", and beneath him were three buttons.
It was at some church fundraiser thing, and there was a kid there that oversaw all the playing. As I recall, the policy was that a certain number of tickets would let you play most games until you died, but when I picked SM64, he told me "Well, you can't really die in this game, so you can play until I get back from the bathroom." And then I died and got the aforementioned Game Over screen before he got back.
Also, I think it started out in first-person view, and switched to third-person once I got into the castle (which, incidentally, was much greyer and blander than normal). The moat was empty (can't remember if it was a new file or not), and I think the bridge was wooden. Inside, I couldn't find the door out. There was a Toad at the entrance, except he said what he's supposed to say in front of Hazy Maze, I think. And I'm pretty sure it didn't have the play with Mario's face thing.
I think I may have sent this to the mailbag a while ago. I know I sent it to SMBHQ's memories thing about five or six years ago, when my memories of it were a bit clearer.
I also had a dream once that Toad was playable in SMRPG, except he was about the same size as Toadofsky. He had an insta-kill attack. I remember that I was in a hotel when I had that dream, because after I woke up, I tried to draw him on the little cheapy hotel stationery pads, but I was too young for my drawing skills to be any good. But the SM64 thing definitely wasn't a dream.