The first Star Coin is floating above the Fuzzy at Point 1. You’ll need the nearby Blocks to reach it, so don’t destroy them until you’ve collected the Star Coin.
The second Star Coin is located in a hidden room. Defeat or avoid the Big Fuzzy at Point 2, then enter the pipe near the wall to the left.
After you pass through the pipe, move to the middle of the room. Hit the POW Blocks when all of the Fuzzies are in range, then hop onto the used Blocks and jump up to grab the Star Coin.
One of the Blocks at Point 3 contains a P Switch. Find and activate the P Switch to reveal the nearby blue coins.
The last Star Coin is hidden near the pipe at Point 4. Use a fireball to defeat the Big Fuzzy to the right, or slip past the enemy when it moves to the left half of its track.
Perform a series of wall jumps to find the Star Coin on a hidden ledge above the track.