Play as Luigi

At the "Select A File" screen, highlight a file, then hold L + R and press A to play as Luigi in Single Player mode.

Secret Challenge mode

Successfully complete the game. Start the cleared game file, then pause the game while at the world map and press L, R, L, R, X(2), Y(2). If you entered the code correctly, the message "Welcome to the Secret Challenge mode" will appear. Similar to the original Super Mario Bros. for the NES, Secret Challenge mode will not let you backtrack in certain levels. To indicate whether a level has a Secret Challenge version, the new right arrow icon will be lit in the top right corner of the map screen.

Secret exit in World 7-4

To locate the secret exit in World 7-4, you will need a mini-Mushroom (in storage, if possible). Make your way past the mid-level point and upwards to the left side of the screen (high up). You will eventually come to a flying "?" block. Use the mini-Mushroom to make Mario smaller and jump onto the block to stop it. Then, use the block to jump into the little opening in the brick wall. Make a "C" jump (backwards C) and jump up and to the left to land at the top of the wall. Go over and you will see a small pipe that only mini-Mario can fit in. Take this pipe to reach the red flag secret exit.

Secret exit in World 7-5

Just before you reach the giant Bullet Bill, you will see a pipe that is covered in blocks. Use the Bob-ombs to blow up the blocks and then access the pipe to reach the red flag secret exit.

Warp from World 5 to World 8

Enter the World 5 Ghost House and get a Mushroom from the blocks. Then, go up the stairs untill you get to a place with three brick blocks on the left side of the screen. Stand on top of them and jump to reveal three invisible blocks. Next, wall jump on the left side to get on top of them. Stand on the middle raised block and duck, then jump to reveal a block with a vine in it. Climb up the vine and a Boxing Ghost will appear. Jump off the vine to avoid taking damage from it. Kill it and climb back up, and enter the door. Kill the two Walking Pumpkins and stand in the middle. The platform will wobble and as long as you stay in the center you should be fine. When it reaches the top, exit and jump on the flag pole. A path will open to the Warp Cannon on the World Map. Enter and use the Cannon to get to World 8.