The chasms throughout this level require you to make good use of the trapeze swings. It helps to come here with the Cat Power-Up, as the ability to climb on walls gives you an edge when making dangerous crossings.
Green Star #1
Your acrobatics (or Cat Power-Up) will be put to the test to reach this Green Star. When you see the tilting platform covered by the spiked roller, you can swing off a trapeze to land on a set of invisible cloud platforms close to the star, or you can simply climb straight up the wall with a Cat Power-Up.
After the Checkpoint Flag, you come across a set of large rotating platforms filled with Piranha Plants. Mushroom Trampolines can help you jump high enough to defeat the larger plants. At the center of this platform is a ? Block containing a Mega Mushroom. Crush your enemies!
Stamp
To the north of the rotating platform, you can use a Mushroom Trampoline to leap on top of a wall to reach the Stamp.
Green Star #2
On the eastern side of rotating platforms, you can cross a small bridge made of Donut Blocks to reach a pipe. You’re warped to a bonus room with a P Switch. Collect the Blue Coins that appear when you hit the switch to earn a star.
Green Star #3
Use a set of trapezes hanging over tilting platforms to reach a Green Star Ring. Collect the Green Coins that appear afterward in order to make the star appear.
Reaching the top of the Goal Pole here can be tough without the Cat Power-Up. Build up as much momentum as you can on the trapeze before you make your jump. With the right timing and momentum, you can nail the landing on top of the Goal Pole.