World 6-Airship (New Super Mario Bros. Wii)
From the Super Mario Wiki
World 6-Airship is the airship level of World 6 from New Super Mario Bros. Wii. It features Mechakoopas and has the first appearance of Rocky Wrenches and the RemoCon Clown. This is also where the player fights Bowser Jr. for the second time.
Mario begins the level near three spinning wheels, along with a ? Block containing a power-up and two Mechakoopas. A Rocky Wrench is then found on a platform, followed by spinning wheels above a pit. More Rocky Wrenches are then found, along with a pile of crates above a Warp Pipe. The midway point is then found. The Red Ring is encountered, along with two wheels and a Mechakoopa. A trail of coins leading to a Rocky Wrench is found, followed by more crates. Another Rocky Wrench is encountered in front of two Brick Blocks, one of which is a Coin Block. More wheels above a pit are then found, and two Mechakoopas can be found on them. Two more Rocky Wrenches are found, along with the Warp Pipe leading to Bowser Jr.
In Bowser Jr.'s fight, the player must climb into their own RemoCon Clown and knock Bowser Jr.'s Junior Clown Car into the electric fence on the walls of the room, or jump on him three times (this can only be done with the Propeller Suit). Players must also be careful not to get rammed into an electric fence. After Bowser Jr. is defeated, he is caught by Magikoopa and ejects Mario and co. from the airship. Upon completion, the Airship leaves and the player unlocks World 7.