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
Complete the game successfully. Launch the deleted game file, then pause the game while on the world map and press L, R, L, R, X (2), Y (2). If you entered the code correctly, the message “Welcome to Secret Challenge mode” will appear. Similar to Super Mario Bros. for the NES, Secret Challenge mode will not allow you to backtrack on certain levels. To indicate if a level has a Secret Challenge version, the new right arrow icon will illuminate in the upper 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 (stored, if possible). Pass the mid-level point and go up to the left side of the screen (top). Eventually you will hit a “?” block. Use the mini-mushroom to make Mario smaller and jump onto the block to stop him. Then use the block to jump into the small opening in the brick wall. Do a “C” jump (C backwards) and jump up and to the left to land on the top of the wall. Go and you will see a small pipe that can only fit mini-Mario. Take this tube to get to the secret exit of the red flag.
Secret Exit in World 7-5
Just before reaching 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 secret exit of the red flag.
Transition from world 5 to world 8
Enter World 5 Ghost House and get a mushroom from the blocks. Then, go up the stairs until you reach 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. Then jump the wall on the left side to get on them. Stand on the raised block in the middle and crouch down, then jump to reveal a block with a vine. Climb up the creeper and a boxing ghost will appear. Jump off the vine to avoid getting hurt. Kill him, go back up and go through 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 you get to the top, get out there and jump over the flagpole. A path to the Warp Cannon will open up on the world map. Enter and use the Cannon to get to World 8.