In Valley of Bowser 2, bring a Super-sized Mario to the maze with the rising and falling floor. Get under an overhang of some sort, and duck. When the floor starts to rise, keep ducking until you're about to get smashed, then spin jump. If all goes well, Mario will go through the wall! This also works the other way around; you can end up in the floor if you duck and spin jump a split-second before the ceiling comes down on you.