World 3-2 (New Super Mario Bros.)
From the Super Mario Wiki
World 3-2 is the second level appearing in World 3 of New Super Mario Bros. The level is a sky-based level, featuring Mushroom Platforms that rise, tilt, and lower, similar to the ones from World 1-3.
This level contains many Mushroom Platforms, and most of them tilt back and forth. About halfway in the level, if Mario goes down a yellow Warp Pipe, he will find the first Star Coin. If the player stays on the pair of dropping platforms, then Mario can reach the second Star Coin. After the Star Coin, there is a moving Mushroom Platform that Mario must ride on. Then, Mario must stay on more dropping platforms, where there is a Red Ring. Finally, there is another moving Mushroom Platform, where Mario can obtain the final Star Coin, but he must avoid the Koopa Paratroopa. After the moving last moving Mushroom Platform is the flagpole.
On the first moving Mushroom Platform, there are three pipes in a row, colored red, yellow, and green. The green one leads to a bonus area. By going through the Warp Pipe on the other end of the bonus area, the player arrives at an area with several Mushroom Platforms that tilt, rise, and lower. At the end of this section of the course is a Red Flagpole, which is the secret exit leading to World 3-B.