Secret Treasure Rooms
There are two secret treasure rooms in Luigi's Mansion that you can access to load up on gems and money: - The first one is located on the first floor, in the south-west corner of the Mansion. After you have sucked in the candle-carrying butler, examine the room with your Game Boy Horror to find a mouse hole. Press A to activate it and go inside to enter the treasure room. - The second treasure room is accessible from the roof top. Use the elevator in the toy chamber to get on the roof, the go all the way to the right and climb up on the chimney. Fall down and you will land in another treasure room.

Capture Nana
Check the balls of wall on the table to make them fall. Now suck one up one at a time and fire them at Nana. Of you miss you must leave and try again. Once you hit her three times in a row, you can capture her.

Capture Slim Bankshot
When he fires the balls into the sky, suck them up and fire them at him. Do this three time to reveal his heart.

Capture Miss Petunia
After getting the Ice Element in you vacuum, go to the third floor bathroom at the north-west end of the corridor. Now you should see her bathing in her bath. Suck the curtain away and spray ice at her. Now you can catch her.

Capture Melody
In the conservatory, start all the instruments playing and then the piano. The ghost Melody will appear, play a tune and then ask you a question. Get it right and ahe will send paper after you. Suck it up and she will look disappointed. Now you can flash her and suck her up. If you egt her question wrong, go out and come back in.

Extra hearts and money
Use your vacuum to clean all lamps, chandeliers, and vases. Most of them will contain either hearts (life) and money.

Finding Henry And Orville
After the twins tell you to hide and you reenter, vacuum the boxes. If the box shakes, open it.

Capture Neville
Enter this one hallway in level 1 where you'll find your first 3 gallery ghosts to capture. The firsts one's Neville. Look the other way behind the rocking chair to see Neville reading a book. Avoid the flying books and wait till Neville yawns. That's your cue to shine the light on him and suck him in!

How to beat Bowser
When bowser throws his spiked bombs at you wait for them to stop moving. Then pick them up with you vacuum. Then you have to wait till bowser lowers his head to breath fire or to breath you into his mouth and shoot it at his mouth the head will pop off and boo will pop out now turn on the vacuum and lower his health points while avoiding the ice blasts that comm from bowsers head. Repeat this process and you will beat bowser.

Get rid of fake doors
Use the Flamethrower element on the annoying fake doors and they will melt and disappear. Note: They will return after you enter another door.

Get Lydia
After capturing Neville, you'll get the key to Lydia's room. follow the map to get there. Once inside the room, you'll see Lydia combing her hair. She won't notice you unless you move the curtain in the background with the poltergust 3000. She will be disturbed by a draft giving you the chance to suck her in.

Beat the ghost in the dining hall
First you must have the fire that comes out of your gun. Then light all of the candles next to the ghost[there are 6 candles]. Once you have done that, you can scoop up the food he is eating. Now made ghosts will show up to give the fat ghost more food. While they are out capture them. Now you can scoop up all of the food there for making the big ghost mad. When he gets up and shoots fire at you, you need to go hide behind cabinet near the door on the right side of the screen. Then he will stop shooting fire at you and just sit there. Now you have to be real quick and go over to him and you can see his heart. Apparently now go scoop him up and you should capture him!

Start Vacuum Without Holding
This code is just plain fun. Walk up to a wall and knock on it by pressing the A button. Then IMMEDEATELY press the R button. The vacuum will activate, without Luigi holding it. Luigi will grab it soon after. This code does not effect anything, but it is fun to try it.

Hidden Mario Items
Madame Meiru will command you to find 5 items that belong to Luig's brother Mario. With each item she can channel herself to the spirit world and provide you with information. After you have found all five items and spoken to her, you can attack her for a key. These are the items and where to find
them: #1 - Mario's Hat - In the washing machine in the laundry room
#2 - Mario's Letter - Near the birdhouse in the backyard
#3 - Mario's Star - In the observatory
#4 - Mario's Glove - In the cinema room
#5 - Mario's Shoe - In the twin's room
Hidden Stuff
To find hidden stuff, get out your vacuum and start cleaning lamps and vases. Almost every second vase has a heart hidden inside and nearly every lamp or chandelier either yields money or health.