World 7-Castle (New Super Mario Bros. Wii)
From the Super Mario Wiki
In this level, there are numerous Skewers that the player has to avoid. They all vary in size and speed. Sledge Bros. also make an appearance here. Ludwig von Koopa is fought again here. Magikoopa forces the fight to take place on three moving platforms which change height at times. Ludwig fires four navy-blue fireballs, then jumps to a nearby platform with flutter jumping. While he is casting his spell is when the player should jump on him.
If the player completes World 7-6, a vine leads them into a tower of the Castle. If they choose this path, they are taken into a hidden room of the castle. If the player goes through the pipe in the room, they are dropped right in front of the door to Ludwig's battle.