There are two parts of the level, the mansion and the basement.
The Mansion is the main part of the level. Mario starts outside of the front Enterance, which entering it will lead Mario to a double floor lobby. If Mario enters the left door on the first floor, he will enter a room with a table, two bookshelves, and a Boo picture. If Mario has the Vanish Cap on, he can go through the painting to meet a room with lots of Boo's with Blue coins, as well as another door leading outside. Back in the room with the bookshelves, if Mario stays in a spot for too long, a chair will fly up from the table, then proceed to damage Mario.
Going through the door at the end of the room leads to a completely empty room besides a large piano which will try to attack Mario if he gets close. Going through the other door in the Mad Piano room leads to the lower-left door of the lobby. Going to the top-left door will enter Mario into a room with a Mr. I and a Boo. Going to the lower right door of the lobby will lead to a room with bridge and a small gap. Crossing the bridge and making it to the other side goes to another room, with a humongous gap and several boos, which this room also leads to the top-right door of the lobby.
If Mario has killed all the Boo's in the first floor of the lobby in Mission 1, he will meet a Big Boo, which upon defeat unlocks access to the second floor. On the second floor, there are a five more doors. On the lower left door, entering will give Mario access to to a room directly over the Mad Piano, which on the door Mario is on the right platform. If Mario enters the left door, he will go to a room with many bookshelves, which books from the bookshelves will fly and attempt to attack Mario. Making it to the other side of this room will lead to a puzzle, which is three books whom Mario must hit in order. The correct way is Top, Right, Left. If Mario doesn't make that pattern, a book will fly at him. If Mario does make it, it will lead to a door to the other side of the lower-left door room, which this side holds a Power Star. Going to the top-left door will enter a few thin pathways over the room with the Mr. I.
At the top right door, Mario will enter a room with another Mr. I and six coffins, two of which hold Red Coins. Finally, entering the right door will take Mario to a room with a platform that is very tiltable. There is also a platform leading up to the third floor. Entering the door on the other side of this room leads to a balcony with a Vanish Cap. On the third floor, there is a door that leads into a room and a painting, which if Mario has the Vanish Cap, he can enter a painting that has the Big Mr. I in it. Entering the double doors leads to another Big Boo, whom on defeat, Mario must make his way to the roof and collect a star.
If Mario falls through either a hole in the mansion or take an elevator in a shack outside the mansion, Mario will enter the basement. Taking the elevator in a small shack with a Mr. I will lead Mario to a small room filled partly with water. Going through a door will lead to a hallway with another door. Entering this door will lead to a room with a large wooden structure in the middle of this room. Once Mario enters this
room, the music will change from an ominous tone to a strange, yet bright circus tone. If Mario makes a full gap around the wooden structure, he will go to a small lake, which is where Mario lands if he fell from the mansion. If Mario enters a door from the side with the lake or the pathway that leads to the lake, he will enter a huge room with many Boo paintings, which one of which has fire spewing out of it. If Mario defeats all the small Boo's here, than another Big Boo will take their place. If Mario defeats this Big Boo, he will get the second star of the level.
Mission 1 - Go on a Ghost Hunt Edit
Mission 2 - Ride Big Boo's Merry-Go-Round Edit
In Mission 2, Mario must either take the shack elevator outside of the mansion or fall in a hole in the mansion. Once Mario reaches his way to the basement, he must make his way to the room with a style of a Merry-Go Round. He must then defeat all the Boo's and the Big Boo to get the Power Star.
Mission 3 - Secret of the Haunted Books Edit
In Mission 3, Mario must make his way upstairs and enter the room with lots of books. He must then enter a correct pattern at the end of this room to open a secret door leading to the Power Star.
Mission 4 - Seek the 8 Red Coins Edit
In Mission 4, Mario must find the 8 Red Coins scattered throughout the Mansion.
Mission 5 - Big Boo's Balcony Edit
In Mission 5, Mario must make his way up to the attic and on to the balcony where the final Big Boo stands. Once the Boo is defeated, Mario can jump onto the roof and collect the Power Star.
Mission 6 - Eye to Eye In The Secret Room Edit
In Mission 6, Mario must make his way back up to the attic, but instead of going outside, he must collect the invisibility cap and jump through the Boo painting. He then must defeat the Mr. I in the room and collect the Power Star.
DS Exclusive Missions Edit
Mission 7 - Switch Star In The Basement Edit
In Mission 7, Wario must be used. Wario must go to the basement and break the black box, revealing a Star Switch. He then must quickly make his way around the room to the star. Due to Wario's slow speed, it is advised the player collects a Mario or Luigi to play as them.