Super Mario Brothers 3 Codes -

 

Control title screen:
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.

At the title screen where you choose to play the original Mario Bros. or Super Mario Bros, keep pressing then as fast as possible. It will look like the Mario standing near the Super Mario Bros. 3 sign is jogging.

Level select:
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.