Crack the screen in Scumm bar   -  After the dart players in the bar hit the balloon, talk to them again and tell them to hit the post on the right hand side of the screen. Talk to them again and tell them to hit "That guy over there". They will throw the dart at the screen and it cracks.

Debug Mode  -  This cheat allows you to activate all the other cheats that are available in this game.
To do it all you have to do type "i want to escape".

Frankenstein  -  Talk to Deadeye Dave about free prosthetic parts until you get a butt, head, liver, foot, stomach, guts, heart, and skin. Combine everything but the skin to make Frankenstein.

Hidden sequence  -  Successfully complete the game and wait until all the credits complete to see an epilogue sequence. 

Hidden items  -  While at the school, ring the fire alarm. Mrs. Rivers will run out. Quickly run inside. Look at the treasure chest where you find the whistle. There will be more items inside. Grab one. Mrs. Rivers will catch you and throw you out. Repeat this to get eventually get everything but the wad of tobacco.

Kill Guybrush  -  In the Swamp in Lucre Island, when the other Guybrush gives you the gun, you can shoot him with it. The gun must be one of the first three things he gives you.

Murray Bites  -  Change in the tent at the diving contest about 12 to 13 times in a row.

Murray's head  -  Type skull during game play and Murray's head will appear with his laughter. Press U to remove the head.

Play Pong with Murray  -  Keep spinning the stool he is on -- to do that try picking him up. When he starts repeating the same warnings to you, face Guybrush the other way and type murryball.

Run easily  -  To make Guybrush run without having to hold [Shift], press [Up] + [Forward] twice and hold it.

Win the game  -  Hold [Alt] + W to win the game.