At the title screen where you choose to play the original Mario Bros. or Super Mario Bros. 3, keep switching the game highlighted continuously. Eventually on the top choice, Mario will appear with a turtle shell and on the bottom Luigi will pop out. Additionally, at the title screen where you choose to play the original Mario Bros. or Super Mario Bros, keep pressing Up then Down as fast as possible. It will look like the Mario standing near the Super Mario Bros. 3 sign is jogging.
Successfully complete the game (you can just use a warp whistle to get to World 8). You can now select any World you want to go to at anytime. If you complete all of the levels (including Hammer Bros., Toadstool Houses, and the casino-type game), you can play any level as many times as desired. This includes the Hammer Bros., the Toadstool Houses, the casino things, and even the fortresses and castles.
Start a new game, playing as both Mario and Luigi. Steal (exchange) all of Luigi's lives that you can (four). Pause the game, then select "Save & Quit". Reload that same game, playing as only Mario. He will now have nine lives, and Luigi will not be around. Note: You can execute this trick at any point in the game if you need a few extra lives. Additionally, successfully complete the game, then go to any world. Go to any spinner (casino). Play it until win an extra life. Repeat this as many times as desired.
Available only through an e-Reader, the Cape allows Mario or Luigi to fly indefinitely, as long as you continuously press Left to stay in the air.
On the title screen after you select the Super Mario Bros. 3 game, look at the 3's shadow. It has a tail and an ear like Mario when he has the raccoon power.
When you chose either Mario Advance or Classic, there will be stars over the Mario brothers part that are equal to how many millions of points your high score is. For example, a high score of 2,163,170 will have two stars.
The Match Game will appear every time you earn a multiple of 80,000 points. (80,000, 160,000, 240,000, etc.). This a mini-game in which you have to match two of the same cards.
Use the following trick to make a coin ship appear on the map. End any level with both the coin and the last two numbers of the point total equal to any multiple of 11. The time also has to stop on an even number. For example, 55 coins and 009844 points. The coin ship is a ship full of coins and an extra life.
A Flute can be found in World 1-3. Hop on the white block toward the end of the level and hold Down on the block for six seconds. Mario will drop down. Finish the level and you will be sent to a chest room containing a Flute. Also on the very first fortress that you encounter, you have to skip across some lava. After the lava, there is a block with a Feather in it, and one of those skeletons that cannot be defeated. Squash the skeleton quickly with the Raccoon Suit on, then get your "P" all the way up so that you can fly. Fly up the right wall and you land on top. Go right until you cannot go further. Then, press Up as you would when opening a door. Inside there is a Flute that Toad gives you. You do not have to face Boom Boom.
The Flutes transport you to certain places, depending on what world you are in. If you are in World 1, it will transport you to the 2, 3, and 4 line. If you are in World 3 or 4, it will transport you to the 5 ,6, and 7 line. If you are in World 7, you can go to the bottom line that leads to World 8. World 2 is always random. If you use two flutes one after the other, you will automatically go to World 8. Note: Sometimes this may not be the exact method for when a flute is used, but 90% of the time it will be this way.
There is a Flute in World 2. Use the hammer you get from the Hammer Bros. on the rock in the top right corner. On the next screen, you will find a Fire Bros. Defeat it for a Flute.
Get the two Whistles found in World 1-3. Use the first one to get to World 7, then use the other Whistle to warp to World 8.
When you get an item you like in a Toad House, get a game over and try again. The Toad House can be done again.
Note: This trick requires an e-Reader. Scan the Super Leaf card that is included with the game when you have a connection with the e-Reader. You can keep scanning until your inventory is full.
Using the frog suit, you can get inside the second pipe on the bottom of the level (found about halfway though the level). Hold Right as you enter the pipe to get to where the giant "?" block is located.