Bumper Ball Maze 2:
Clear all 50 Mini-Games on Mini-Game Island.

Bumper Ball Maze 3:
Set new records on Bumper Ball Mazes 1 & 2.

Eternal Star Stage:
Get 100 stars

Bowser's Magma Mountain:
Get 1000 coins and buy the key in the shop.

Hints:
To get a lot of coins go to the mini-game hut, then go to the pot and set it to one player (but have 4 controllers in.) Set the computer to hard and give everyone handicaps of 50. Play a standard game as you would anytime. When it is the last turn, pause the game and set the computer players to human. When the game ends you will not only have your coins but theirs too.

New Title Screen:
After you finish a game with a character, that character will be the star on the title screen

Easy coin collection:
Pick 3 characters and play until right before the final round then stop play and turn the characters into player 2, 3 and 4. Now you're all alone for the coins?

Get Some New Tunes:
In the mushroom shop purchase a record to unlock new songs on Bowser's Magma Mountain and the Eternal Star Stages

New items:
After finishing the Eternal Star Stage you can buy new stuff in the shops

a.. Plus Block (200): Get a random number of coins.
b.. Minus Block (100): Lose a random number of coins.
c.. Speed Block (200): Numbers 8 to 10 appear on the block only.
d.. Slow Block (100): Numbers 1 to 3 appear on the block only.
e.. Warp Block (200): Players change positions on the board.
f.. Event Block (200): Boo, Koopa, or Bowser will appear.
g.. Mecha Fly Guy (100): Counts rotations of the control stick.
h.. Record (50): This lets you listen to the game's tunes in the Option House.
i.. Talking Parrot (50): Enables a voice test in the Option House.
j.. Lucky Box (100): Get 10 percent interest on coins.
k.. Casino Box (300): Bet your coins and get double or half

Extra Items:
After you beat the Eternal Star save it and turn the system off. Then turn it back on and go to the Mushroom Shop and there is more stuff. There is a No Boo sign and a No Koopa Troopa sign. Also a Credit Record. But you have to buy all the other stuff thats in there like the blocks and other stuff before you can get those items!

Tons of Money:
Go to the Mini-game stadium. Go inside the pot-o-skills. To do this code you must play the mini-game stadium in 1P. Pick your character,and pick any 3 computer characters. Select yes for the handicap. Now set the handicap to 50 coins. Then set the computer characters' skill level to "All Hard".Now set the number of turns to 30.Now begin playing. When the screen says "Last turn" turn the 3 computer characters to player2,3,and 4.You may get from 700 to 1000 coins. If you have the casino box with you try to double the amount of coins you get in the end.

How to get gumball machine:
Buy at least 30 Minigames

Swing on Vines in Pirahna Pursuit:
In the 1 vs. 3 minigame Pirahna Pursuit you can swing on the vines you see hanging down. This especially comes in handy when you need to swing over falling logs. Try and swing on them whenever possible just to be safe, because it dont slow you down none. You have to have good timing to be able to do it, though.

Get coins and stars without playing:
Go into the warp pipe and select a 1 player game. Pick any board. Get all started and on the first turn press start. Go to controller settings, pick your character, press A and make it computer operated. Before the last turn begins press start, go to controller settings, pick your character and set it back to player 1. Then play the last turn and at the end of the game you get all the stars and coins without playing the game!