Throughout this level you’ll find many cogs. You need to pay attention which direction they spin because you could wind up falling to your death by running too fast in one direction.
Start by crossing the first two cogs the drop down near the big one. Defeat the Mega Piranha then grab the Boomerang Flower from the ? Block since you need it this level. Climb back up and this time ride all the way across the cogs. You’ll notice the next few are large and have teeth you can stand in. Ride the one higher up around to it’s peak then toss a Boomerang out to grab Green Star #1 . Continue to the end of the cogs and into the pipe to reach the Checkpoint Flag .
Now the journey gets a little tougher. You need to climb the cog wheels that spin on the wall but they have Piranha Plants on them and two Mega Piranhas lurk up top. Use the Boomerang to take them out as you climb slow and steadily up to the pipe. Ant Troopers are moving up and around the hole in the ground, one carries a Boomerang Flower so if you time it you can slide down the backside of the wall and grab it then the Stamp on the platform below.
Use the pipe to get back up top then race up the cogs to another area with Ant Troopers. Take them out and jump down the hole to a Mystery Box. You wind up on a large cog that constantly turns so you need to avoid the obstacles to reach Green Star #2 .
Head back up top and proceed down the cogs, taking your time so you don’t launch off then into the pipe. You can see the final Green Star in the distance, but there’s a trick to getting there. Leap from the large cog at the end but dodge the Goal Pole, instead going behind it. Perform a long jump from the corner or use a Tanooki Suit to land on the island at the back end. Capture the Rabbit for Green Star #3 then pick up the Green +Clock for some bonus time before returning and capping the Goal Pole.