Level 6-3 (Mario vs. Donkey Kong: Tipping Stars)
From the Super Mario Wiki
The course is made up of pathways crossing into formations of Pink Block spaces. There are also vertical Pipes connecting some pathways. A few Thwomps are found above places with clusters of Pink Block slots, where the player can put Pink Blocks to prevent the Thwomps from falling on the Minis. One Mini Mario and one Mini Peach start inside a tunnel at the bottom of the stage, while the rest begin at a much higher point. The Goal Door is located on the bottom left, behind a column of two Pink Block slots. To reach it, the Minis should enter the nearby Pipe from the top right, where a Thwomp normally resides.
The M Coin is found at the top entrance of the short Pipe next to the bigger Pipe on the right. The players must use Pink Blocks to guide the Minis to the Pipe and the M Coin.