This level starts you in the middle of a large field, and before you can leave it, you must find five Key Coins to unlock a Warp Box. This field also contains a lone Green Star for collection.
The first Key Coin is in front of where you start the level, surrounded by Peepas that appear when you get close.
One Key Coin is very close to the Warp Box you need to unlock. Hit the Red POW Block on the ground to create a set of steps that let you reach it.
North of that Key Coin, you can find another behind a block wall. Destroy it by hitting the Red POW Block and you get easy access to the Key Coin.
The fourth Key Coin is over an invisible cloud platform near a pine tree. The platform will rise up to the Key Coin once you stand on it. The invisible cloud platforms is constantly moving, and it will not wait for you to help with reach the Green Star.
The hardest Key Coin to retrieve is up on a balcony (5) with no immediate way to reach it. Look for a particular door somewhere in the fog (6). Entering it will take you straight to the Key Coin.
Green Star #1
A swarm of Peepas has Captain Toad surrounded, and he won’t give you a Green Star until they’re gone. If you run to the other side of the field (7), you can find a Super Star by ground pounding in front of a tombstone.
Dash back over to Captain Toad and take out the Peepas before the Super Star wears out!
After seeking out all of the Key Coins, you might be low on time. Don’t miss the Green + Clock at the start of the raft ride!
Green Star #2
When you encounter two Snow Pokeys in between a pair of Mystery Boxes, take the box on the right to reach a bonus room. Approaching the Green Star in this room causes it to vanish. Instead, grab one of the nearby snowballs, run away until the star reappears, and throw the ball at it.
Green Star #3
This star is floating off to the side of the docks. You have to throw a snowball (or use a boomerang) to safely retrieve it.
Stamp
During the Dash Panel-boosted run to the final Warp Box, take the side route to the right, making sure to jump over a gap in the walkway. The Stamp is on a small island in the middle of the bog.