World 5-A (New Super Mario Bros.)
From the Super Mario Wiki
This level has Stretch Shrooms. Mario must time his jumps, because not all of the platforms move at the same time as each other. After the midway point, Mario can get the first Star Coin by going down to a Stretch Shroom. He needs to hit a ! Switch to return. Just after that, Mario should find a single block. If he hits it by running and jumping, a Beanstalk pops out, taking him to an area with the second Star Coin. The player should later see two Mushroom Platforms that are able to touch each other. Mario should stand in between them and jump when they shrink, getting the last Star Coin. Then, Mario reaches the flagpole.