Many of the platforms in this level are supported by two columns. Each time you spot a pair of columns, stand in the gap between them. Doing so will reveal hidden coins or Blocks.
The ? Block at Point 2 contains a Gold Flower. To reach this platform, use a Super Leaf to fly up from the ground or glide from the platforms to the right.
The first Moon Coin is located in a hidden area. To find it, hop into the water, and enter the passage at Point 3 before the current sweeps you back to the start of the level.
The Moon Coin is floating in the center of the area. Avoid the water currents and circling Peepas as you swim over to collect it.
The second Moon Coin is floating above the platform at Point 4. Search the platforms on either side of this location to reveal two sets of Blocks, then use the Blocks to reach the Moon Coin.
The third Moon Coin is in a hidden area. Use a Super Leaf to fly or glide up to the platform at Point 5. Locate the Invisible Block above you, then climb up the revealed Beanstalk.
The Moon Coin is hidden behind the Big Whomp on the central platform. Dodge the circling Peepas, coax the Big Whomp into attacking, and grab the Moon Coin.
Before you pass through the Red Ring at Point 6, defeat the Whomps on the nearby platforms. It’s much easier to collect the red coins with these enemies out of the way.