28 P-Wings:
Complete the game, then press Start at the ending screen. The next game will begin with 28 P-Wings per brother.

 


Always get three stars:
At the end of most levels (in which you get a card). Use full speed with marios that allow you to run, and hit the bottom left hand corner of the "card block". If done right you will be able to get that star each time. MUST DO THIS EACH TIME AT END OF THAT LEVEL.

 


Avoid Damage From Bowser:
When fighting Bowser in the final level of the game, his lower half will not do damage to you. That means you can avoid damage from his ground-pound attack by ducking if you have obtained a power-up at some point, or, if Small Mario, you can walk under him and through him without sustaining damage.

 


Beat Fortress via N-Spade:
In the game, you need to wait until the N-Spade card game - which appears with every 80,000 points you earn - spawns and moves to the spot of a fortress on the overworld map. If you go there now and play it, the fortress will as if you had beaten it afterwards, being collapsed and unplayable. Note, however, that the bridges and locks affected by defeating the fortress normally will still not unlock or reappear, so only do this when these things are not required.

 


Change forms:
Press Select while playing a normal game to change into different Marios or Luigis (Mushroom, Fire Flower, Super Leaf, Frog, Tannokie, and Hammer Brother).

 


Desert World Whistle:
Towards the end of the Desert World you can obtain another whistle. In the top right corner in the far right hand corner of the world there is a rock directly next to the path. Use the hammer you obtained from one of the Koopa Battles to break it. Once you've found it though you must defeat two fireball spitting Koopas to get it make sure you at least have a mushroom before going into this battle just to be safe.

 


Double Warp:
Receive two whistles and use one to get to the warp room. In the warp room use the second whistle which will take you to the last part of the warp room. This will get you to level 8 to defeat king Koopa.

 


Game Genie Codes:
All codes (except as noted) work for Luigi as well as Mario.

SLXPLOVS Infinite lives for Mario and Luigi
AEKPTZGA 1 life for Mario and Luigi after continue
AEKPTZGE 9 lives for Mario and Luigi after continue
ELKZYVEK Power Jumps
EZKZYVEK Super Power Jumps
EAKZYVEK Mega Power Jumps
GZUXNGEI Multi-Jumps

With the next code, if you let Mario or Luigi drop too long, you can't sky walk until you touch the ground again

SXEZSKOZ Skywalker
OXKZELSX Super speed running
XVUXNUEE Turbocharged running

You must be Raccoon Mario for the next code to work

AANZKLLA Can raise power meter while standing still so that you can fly from a standing start

PEUZUGAA Start on World 2
ZEUZUGAA Start on World 3
LEUZUGAA Start on World 4
GEUZUGAA Start on World 5
IEUZUGAA Start on World 6
TEUZUGAA Start on World 7
YEUZUGAA Start on World 8
YPXXLVGE Mario (not Luigi) can re-use items again and again
SZUEXNSO Restore powers after playing an action scene (e.g. if you were "Fire Mario" on the map screen, then entered an action scene, died or changed to "Frog Mario,"you would return to the map scene as "Fire Mario")

ZEUXKGAA Start the game as Fire Mario
LEUXKGAA Start the game as Raccoon Mario
GEUXKGAA Start the game as Frog Mario
IEUXKGAA Start the game as Tanooki Mario
TEUXKGAA Start the game as 'Sledgehammer' Mario!

If you use any of the next five codes to defeat Bowser, stand in front of the door and hold "Up". as soon as the door opens, you will pass through into the chamber where the Princess is held. If you don't do this, you may get caught in Bowser's time trap and the game will pause forever!

 

XUKXGLIE Start and stay as Super Mario
UXKXGLIA Start and stay as Fire Mario
NXKXGLIE Start and stay as Raccoon Mario
OUKXGLIE Start and stay as Frog Mario
XNKXGLIE Start and stay as Sledgehammer Mario
SZKIKXSE Invincibility after changing up from Super Mario (e.g. to Raccoon, Frog, etc.)With all of the following codes, you will find that you change into Super Mario if you die again:

AEOSSZPA + PAOZTGAA Change to Super Mario if you fall off screen and die
AEOSSZPA + ZAOZTGAA Change to Fire Mario if you fall off screen and die
AEOSSZPA + LAOZTGAA Change to Raccoon Mario if you fall off screen and die
AEOSSZPA + GAOZTGAA Change to Frog Mario if you fall off screen and die
AEOSSZPA + IAOZTGAA Change to Tanooki Mario if you fall off screen and die
AEOSSZPA + TAOZTGAA Change to Sledgehammer Mario if you fall off screen and die


Getting the boot:
Hold Y and press Select.
Hammer Suit:
The hammer suit will make you invunderable to fire and you can kill ghosts with your hammers.
Random world:
Wait until Mario and Luigi begin running around during the opening sequence. Press random buttons on the controller. The game will begin at a random world after the number of players are selected.


Skip World 7-1:
At the start of World 7-1, there is a doorway you're meant to go through. Instead of doing that, run at it and jump at its top-right corner. If done with ample acceleration (and sometimes crouching just before jumping - that can help) you can glitch into the wall and skip the majority of the level.


The Money Ship:
This will only work once each on worlds 1, 3, 5, and 6. Also, there must be at least 1 Hammer Bros. on the map.

You must clear any level with the following conditions:

1) The number of coins you have must be a multiple of 11. (11, 22, 33.....)
2) The second digit from the right in your score must equal the ammount of coins you have / 11.
(So if your score was something like 0000045530, you must have 33 coins.)

To help alter your score, you get 10 points for every brick you destroy and 50 points (or something) for every second left on the timer when you clear the stage. If you met the two requirements before clearing the stage, "make sure the timer is on an even number" when you touch the goal.

At the end of the money ship, you'll fight two Boomerang Bros. Whatever you'd normally get from the Hammer Bros. will be your prize.

Usa Usa
Put in usausa in the game genie and more enemies will appear in weird spots. And also, the backround will be oddly colored.

 

Warp to Level 8:
If you want to go straight to level 8, you must use a Warp Whistle to proceed to the Warp Zone, then use another warp whistle IN THE WARP ZONE. You will be transported to the level 8 pipe at the bottom of the screen.

 

Warp Whistle II:
In world 2, after you beat Level 4, there is a stone right beside 4.Use the hammer and then there is a path that opens up.Fight the fire brothers and after you do that in the box is the Second Whistle. 

Warp Whistle In World 1, Fortress 1:
In the fortress in Grass Land, World 1, there is a secret room where there is a chest. That chest contains a legendary Warp Whistle. There are only three of them in the game. When you get to the part of the fortress where there is a Dry Bones, a Koopa zombie. Hit the ? block as Super Mario or Luigi, and get the leaf the pops out from it. Run from where the door is, and fly up until you hit terra firma. When you hit a dead end, press up on the controller. You'll fall from a height and a chest will appear. Run through the chest, and you will get a warp whistle. 


Whistle Room:
Go to world 1-3. Towards the end of the level, there should be a white rectangle floating in midair. Jump on it, then squat down. In a few seconds, you should fall through. Go to the end of the level. In a few seconds, you should see either Mario or Luigi { whichever Mario Brother you are } on a platform on the left side, and a Mushroom Person on the right. In the middle of the screen, there should be a box. Run to the box, and press B. A whistle should pop out. To use the whistle, you should be on the level select screen. Press B, and there at the bottom of the screen in a pink strip should be a whistle. Scroll over to it and press A. It will take you to a Warp Zone. Choose a world and press A. You can use your whistle in that game only.
White Block Invulnerability Glitch:
Whenever you find a white block (such as the one in 1-3 that leads to the Whistle), stand on it and hold Down until you go through it. Then enter a pipe. In most cases, once on the other side, you'll be unable to be hurt by enemies for the remainder of the level (although sometimes also invisible).


World 3-Fortress Door Glitch:
In World 3's first fortress (just after 3-3), there are several doors you're meant to go through in the level, guessing which is the correct one. If you enter a door and it's wrong, you can immediately press Up before falling to go back through the door. Further, doing this on the third and fourth doors will warp you, instead of to the gray pipe like the other doors, straight to the boss room.