World 6-Bowser's Castle

This level is similar to World 8-Bowser's Castle in New Super Mario Bros. Wii. In the first section of the level, there will be rocket engines on the rope moving near the lava. Then Podoboos and Dry Bones walking near the stage. The Rocket Engines will starting turning on and off near the middle of the first section. Near the stages going up, on the very right, there will be a Brick Block which will turn into a Gold Block. In the second section, Mario/Luigi must ride on the Snake Block. Before the blocks pass the platform with the Star Coin, the player must jump down to the platform to reach the Star Coin. Then the player must avoid the Rocket Engines while the Snake Blocks reach the platform on the door that leads to the third section. Once the player enters the third section, the Koopalings will ride on Bowser's Koopa Clown Car and try to blast the player. In order for the player to dodge, they must go behind the walls although the platforms are moving. If the player is shot, they will temporarily turn to stone. Near the middle of the section, there will be sets of Donut Lifts. On the first set in the middle row, the player must ride down the Donut Lift to get the Star Coin. After getting the Star Coin, the player must jump on another Donut Lift or the platform in order to stay alive. Then the player will enter the room to the final battle.

The final battle is the same as in World 8-Bowser's Castle from New Super Mario Bros. Wii. Instead, the player gets a checkpoint right after the gate and gets three Item Blocks containing two Fire Flowers and a Raccoon Leaf. After the player gets the power-ups, they must go up the steps and dodge the fireballs that Bowser blows and then finally battle Bowser. Like most of the previous games, Mario must get pass Bowser and press the ! Switch to knock him into the lava. Like New Super Mario Bros. Wii, instead of Kamek sprinkling Bowser and getting knocked out, the Koopalings sprinkle their father and get knocked out when he is enormous. Instead of going to the right to rescue Peach, this time the plumbers must go up the platforms before the lava reaches him. Bowser will smash the platforms and when the player reaches the top Bowser will jump and they hit the giant ! Switch. The lava then moves away making Bowser fall out of the castle and Peach is rescued.

Later on, the Koopalings put Bowser into the Koopa Clown Car but fail once Bowser fits and the Koopalings do not so they are knocked down to a tree.

This course is never selected in the Coin Rush game mode, due to the sheer length of the Bowser battle.

Star Coins

 * Star Coin 1: The player must jump straight up while on top of the third Rocket Engine to reveal a Hidden Block with a 1-Up Mushroom in it. The player then must climb that block to reach a secret area with the first star coin.
 * Star Coin 2: In the second section of the level right after Mario go on the Snake Blocks, near the Item Block, jump down to the platform to reach the Star Coin before the Snake Blocks pass the platform.
 * Star Coin 3: In the third section on the first set of Donut Lifts in the middle, the player must ride down one of the 2 middle Donut Lifts to get the coin. Immediately after getting the coin, the player must jump off the Donut Lift and go to another one.