World 1-Castle (New Super Mario Bros. Wii)
From the Super Mario Wiki
World 1-Castle is the first castle level in New Super Mario Bros. Wii and the final level of World 1. It is unlocked by completing either World 1-5 or World 1-6. The level introduces Thwomps and Big Thwomps, which make their first and only appearances in the game here. Larry Koopa awaits the players at the end of the level; defeating him allows the players to advance to World 2. This is the first level to feature the castle theme.
This castle is filled with lava and features many cogs. Mario and co. must hide in the holes in the gears to avoid being crushed. If the players ride one of the gears upward, they can find a small area with coins, a Propeller Mushroom, and two 1-Up Mushrooms. After the midway point, multiple Thwomps and Big Thwomps are encountered. A Red Ring is found before a row of Thwomps. Larry Koopa is fought again at the end of the level. In this fight, Magikoopa animates five platforms, causing them to start moving up and down. The first, third, and fifth go the opposite way of the second and fourth. As in the tower battle, it takes three hits to defeat Larry.