Play as Luigi
Press R at the world map.
Successfully complete all 96 goals to get another color scheme for the world map, alternate enemies, a new introduction sequence featuring Yoshi, and other changes.
Music from Mario Brothers
Enter any of the special levels and remain on the world map. Leave the game idle until the music changes.
Change coins from Yoshi to Princess
Collect all five Yoshi Coins from each level. An animation will appear showing them change from Yoshi Coins to Princess Coins.
Easily Get Yoshi
Go to Yoshi's Island 2, pass the koopas and the first 3 boxes, then hit the next 2 and in 1 of them is Yoshi.
Get Fly Power Easily
Go to Donut Land 1 and jump on the first flying guy, then press start and go back; then do the same thing to have an extra feather.
When Yoshi eats a multicolored shell, he will be able to fly for a short time.
Replay castles and fortresses
After you defeat Bowser, all of the castles and fortresses you defeated will be reopened so you can go back to them.
Save best scores in special stages
Once you complete the special stages, you will be able to save your best scores on them. The bottom of the screen appear like: BEST (score) M or L (which character set the best score) (current score).
Stars for points
For every million points, one star will appear on the "Choose a game" screen on top of the type of game.
Warp to World 4
In level 1-3 go to the area just before the brick background. Pick up the plants until you get a bottle. Then go past the brick background until you find a pot and throw the bottle on it. Go through the door and down the pot into World 4.
Top Secret Area
On the world map, go to the donut plains ghost house. You must have a feather for this to work. Enter the ghost house. Walk right until you get to a hole. Turn around and run to the left (hold b) Jump into air and you will fly because you have the feather. On the ceiling there is a gap to the left. Fly into it and land to the right of the gap. Walk until you fall down the first hole you come accross. Go through the door down the bottom of the hole and finish the level. You have unlocked a new level above the ghost house. You can get mushrooms, fire flowers and feathers and yoshis. Don't forget to save!
Are you tired of looking for ways in the 'cheese bridge area' to unlock the level below it 'Soda Lake'? Here's how to do it. You need the feather so you can fly. At the start of the level take off and fly till you go past the chainsaws near the end of the level. You will see the end goal.
Fly under here->
Once you fly under the goal there will be another one behind it. Go through there to unlock soda lake.