Metal-Head Mario Can Move!
From the Super Mario Wiki
Metal-Head Mario Can Move! is the third mission of Hazy Maze Cave in Super Mario 64 and Super Mario 64 DS, though it is renamed Metal-Head Wario Can Move in the latter due to Wario being the only one who can turn metal. The mission involves using the Metal power-up to activate a Purple Switch underwater.
From the start of the level, the player has to take the path on the left and make their way to the underground cavern, similar to the first mission. Once the player reaches the cavern, they need to hit the Green Block in the N64 version or the ? Block as Wario in the DS version to turn into Metal form. Once the character has turned to metal, they need to quickly follow the path into and under the water that leads to a Purple Switch. Pressing the switch will open the nearby gate blocking the door into the room with the Power Star. The Star rests at the end of the room, and the player needs to do a couple of long jumps to cross the gaps to reach it.
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