World 5-Castle (New Super Mario Bros. Wii)
From the Super Mario Wiki, the Mario encyclopedia
The level begins near Lava Bubbles jumping out of the lava, along with two ? Blocks, one of which contains a power-up. A round, spinning fence can be found, followed by a few more fence over the lava and Lava Bubbles. Green fireballs from Iggy begin to attack from off-screen. Above the fourth fence, a ? Block containing a Propeller Mushroom is found. A section with more Lava Bubbles follows, along with another fence. A Dry Bones is found, along with a section of fences that raise and lower above the lava. Spinning fences with bars that act as solid platforms are found, along with a Red Ring. A Dry Bones is found, along with the midway point. Another section of fences that come out of the lava is found. Two more spinning fences are found, along with a ? Block containing a Propeller Mushroom. Jump Blocks allow the player to reach the boss door.
The boss battle has Iggy with his pet Chain Chomp, which grows after being assisted by Magikoopa. It drags him around the room, and Iggy, who is riding in a seat attached to the Chain Chomp's chain, occasionally shoots spells. There is a platform in the middle of the rectangular stage with two Donut Blocks, and six Jump Blocks, three on each side of the room. When Iggy is attacked, the Chain Chomp glows red and jumps in random directions. When beaten, Iggy and his Chain Chomp fall off screen and Mario progresses to World 6.