World 4-Airship (New Super Mario Bros. Wii)

 is the first Airship level in New Super Mario Bros. Wii. Completion of this level allows the player to unlock World 5.

Layout
The level begins near some crates, followed by a section where Mechakoopas and burners that rotate 180 degrees are found. Two ? Blocks are also found, with one containing a power-up. The player then enters a section with burners on the ceiling. To the left of the area, another ? Block is found, along with a crate containing a 1-Up Mushroom near a burner. The midway point is next, along with a large amount of crates, one of which contains a power-up. Another Mechakoopa is found, along with another burner. A group of Warp Pipes, a Red Ring, and another Mechakoopa follow. The next section contains cannons and pipes that release Bob-ombs. There are stationary burners on the ground, causing the Bob-ombs to explode if they touch the flames. A POW Block is found, along with two more ? Blocks. More cannons releasing Bob-ombs are found, along with rotating burners. Two more Warp Pipes releasing Bob-ombs are found, along with a Warp Pipe that the player can enter. The player enters an area where Propeller Blocks are found, allowing them to reach the boss area.

The boss of the airship is Bowser Jr. in his Junior Clown Car. The player must propel up with Propeller Blocks, or as Propeller Mario, and stomp on his head three times. The Propeller Blocks can also be utilized as weapons, dealing damage equal to a single stomp when thrown at Bowser Jr. After Bowser Jr. is defeated, Magikoopa flies up with Bowser Jr. They then eject Mario and gang from the Airship, which flies away, forcing Mario to chase it to World 5.

Star Coins

 * Star Coin 1: The first Star Coin is in a small alcove in the ground, next to the first long burner. Mario and co. should wait for the burner to turn to the left, then go for the Star Coin.
 * Star Coin 2: Shortly after the midway point is a green Warp Pipe covered by crates. Mario and co. must Ground Pound through a crate and into the Pipe to be taken to an area with two screw rides. The second Star Coin is floating over the second one.
 * Star Coin 3: The third Star Coin is to the bottom-left of the yellow Warp Pipe leading to Bowser Jr., blocked off by a crate. Mario and co. must destroy the crate with a Bob-omb to make the Star Coin accessible.