This is a stealth level. It looks like a castle level. Avoid the spotlights or an alarm will sound and Cat Bullet Bills will be fired and home in on your location. Grab a Tanooki Suit from the item block near a spring enemy. You'll cross a gray brick floor. Be careful about avoiding the spotlights as the Cat Bullet Bills can destroy the bricks. Past the long stretch of gray bricks, you'll find the first Green Star high above the solid floor in the path of a moving spotlight. Use the spring enemies to get it.
When you're past the spotlights circling each other, go behind the wall to the midpoint. You'll be hiding from the spotlights behind the walls. Another spotlight illuminates the stamp over some brick and item blocks, so be careful when you try to get it. There's a crack in the wall. Lead a Cat Bullet Bill to the crack to reveal a Mystery Box. There are brick stairs to the second Green Star. Cat Bullet Bills will appear and destroy the bricks. Move quickly. There are Red Coins ahead if you want them. Climb up the stairs and lead the Cat Bullet Bills to the third Green Star, which is surrounded by bricks. The Cat Bullet Bills will break the bricks so you can reach it. At the top of the stairs is the flag.
The stamp is of Toad jumping.