World 4-2 (New Super Mario Bros. Wii)
From the Super Mario Wiki
World 4-2 is the second level of World 4 of New Super Mario Bros. Wii. Like with several other levels in the game, the player has the option of playing World 4-3 as opposed to this level. The completion of either level results in a path to World 4-Tower.
Mario starts the level on a rocky area. Shortly after two pairs of a Brick Block and a ? Block each is a Donut Block bridge. Mario must get to the other side of the bridge while avoiding jumping Cheep Cheeps. Near the end of the bridge is a Brick Block with a P Switch inside, and if Mario hits it, it spawns coins. Next, Mario will encounter a Barrel with a Star Coin above it. The midway point is located after move of these barrels. A ? Block to the right of the midway point contains a Super Star, and the next section of the level involves ledges that Mario can sidle across. The area also contains wider Donut Blocks, with one being below the final Star Coin. After more jumping Cheep Cheeps is the flagpole.