Codes and Cheats
Change the game to it's Alternate Form
Complete all 96 goals in the game to make the game change to it's Alternate look. This changes the World Map's color, Enemies and more.
Extra Levels From Star Road
If you find and complete the alternate (key) exits in all Star Road levels, you will unlock a set of special levels acessable from the mountain in the middle of the main Star Road map.
Hear the Original Mario Bros. music. Go to the special levels (place with Tubular, Groovy, etc.) Still on the world map, leave the game alone for a few minutres and you'll hear the music change.
Beat the game (defeat Bowser) and the intro changes from the usual 'find the princess is missing, play scary music' to a sequence where you see the princess riding on a Yoshi with another Yoshi carrying a picnic basket.
Play as Luigi
In the world map where you get to select levels and such press the R button and then you will be able to play as Luigi. Luigi has a few different moves then Mario, one being that he can jump really high.
Re-Do Fortresses and Castles
Once you beat the game you will be able to re-do Fortresses and Castles.
At the first ghost level, have a feather. Go backwars instead of forwards and fly up to the sky. Continue on the platform in the sky until the end of the level where there will be a new exit. Go through the exit to unlock an extra level which you can stock up on unlimited mushrooms, fireballs, feathers, lives, and Yoshi.
Yoshi Coins to Princess Coins
To change all the Yoshi Coins to Princess Coins, collect all five Yoshi Coins from each level. After you collect them all, watch the in-game movie to see the coins change.