Although tricks and deception are the Boos' specialty, they aren't above resorting to brute force to impede your advance. Meet the Broozers, thuggish boxers that can punch through solid blocks. Avoid their attacks and use their disregard for causing property damage to your advantage. Even after you get past the flailing pugilists, the mansion's elevator can give you a scary ride!
Remain stationary at the start, as the Broozer enemy is introduced. These mad boxers blindly flail around in your general direction, destroying most blocks in their path. They are fairly resilient, able to take a couple of stomps and fireballs before getting knocked out. You don't necessarily want to destroy them, as their ability to break solid blocks proves to be very useful in this stage. Up the first ladder, you will encounter the next Broozer charging at you from the next staircase. You should defeat it so that it doesn't interfere with the following section of the course.
Up one more staircase and you will see some blocks blocking your way forward. Fortunately, there is a Broozer behind the wall of blocks who clears a path for you. Wait until it falls on to the same level as you, then jump up and stand on the gap it created. The Broozer will still rush at you, but since it cannot jump, it will just break the blocks directly below you. Go through that newly-made opening, defeating the Broozer if you wish, and wall jump up the vertical shaft. At the top, you can find the first Star Coin.
Go back to the first hole made by the Broozer, and continue climbing up the stairs. You will soon see a door on a ledge halfway up a flight of stairs. Leap to the ledge and go into the door. You will end up in a room with six Broozers and some destroyable blocks. Quickly wall jump up these blocks to get to the top level of the room, where you can get the second Star Coin. Too slow, and the Broozers will break all the blocks you need to wall jump up. Whether you obtained the Star Coin or not, return to the main course through the door.
Head up the staircase, where you will encounter another Broozer. If you need a power-up, have it destroy the one-tile wide pillar under the trio of question-mark blocks. The middle block is the one with the power-up. There will be one more Broozer after that, but you will be safe as long as you remain on the stairs where the previous Broozer was on. Next up is a particularly steep staircase, where yet another Broozer will approach from above. At the top, the final Broozer will rush at you from the left.
After the Broozer, jump up a few more platforms to get to the lift. This colorful platform will rise up to the top, where the exit is, but it's not without its odd quirks. At first the lift will ascend to a certain point, then start jerking violently to shake you off. It will continue upward slowly, before suddenly dropping back to its initial position, then it finally shoots up to the top at high speeds. Luckily, there isn't any enemies other than a lone Boo in this portion, so you just have to focus on staying on the lift. At the top is the door that leads outside, where the flagpole is.
- Against the third Broozer, stand below the platform it is on and have it destroy the wall, then jump up after it falls to the lower level. Make it destroy the wall of blocks below, then go into that gap. Here, wall jump up the shaft to get to the Star Coin.
- Jump to the first door you see and go into it. Once you enter the room, quickly wall jump up the blocks before the Broozers destroy them. If you're quick enough, you can reach the coin at the top of the room.
- Once you've chosen the path that leads to the secret exit, you will have to board a lift. Try to stay on the right side of the lift, and hug the right wall once it shoots upward. You should be able to get into an opening of the right wall near the top, where the Star Coin is located.
Near the base of a noticeably steep flight of stairs are a set of three coin blocks. Jump up to bump into three hidden blocks above them. Get on to the middle block then duck and jump (simply jump if you aren't tall Mario) to hit another hidden block. This makes a vine that extends to the ceiling. Climb up until you get to a door behind some blocks. Have the Broozer here break the blocks. It will just barely miss you as it destroy the wall and falls down if you stay on the vine. Go in the door and you'll end up on a lift identical to the one at the end of the main stage. It even moves in exactly the same way. Stick to the right side along the ride, and when it's on its final ascent, quickly move to the opening in the right wall as you pass by it. You can get to the final Star Coin this way. Hit the lone block here to climb to the top of this portion, where the lift would have left you on. Go left and go through the door to arrive at the red flagpole.
This secret exit creates a path to the World 5 Cannon, which blasts you to World 8, Bowser Jr.'s home turf. This is the last cannon in the game, so there's no more major shortcuts from now on!