How to play as Luigi (as 1P) in Super Mario World
Are you a fan of the green stache guy and think he deserves the top billing? It might not be entirely obvious, but there is a way to play as Luigi as the main character in Super Mario World in single player mode.
Like most Mario games, obviously Mario is the main character. In more recent releases such as Super Mario 3D World and New Super Mario Bros. Deluxe, you're given the option to choose characters, so you can be Luigi if you so desire.
In Super Mario World for the Super NES (which is also available on Nintendo Switch Online), it's actually possible to play as Luigi as 1P, but there's a trick you need to do.
How do you play as Luigi in Super Mario World?
Start a 2 player game with a single controller. (In Super Mario World, the 2 player mode normally alternates between Mario and Luigi and can be played with a single controller)
On the world map, hit L or R and transfer all of Mario's lives to Luigi. Mario will be left with a single life, since the game doesn't let you go directly to zero.
Start any level with Mario and make him die in any way you want, Mario will get a Game Over. Press start to close the lives screen to ensure Mario will be stuck at 0 lives. GG!
Luigi will be the playable as 1P for the rest of the play session (until you have a game over or turn off the system), and as a plus he will start with 9 lives!
In the original Super Mario World, Luigi plays exactly the same as Mario, he just looks green from a colour swap, that's all. Beating the game as Luigi also has him in the ending sequence, allowing him to steal his brother's girl, but Princess Toadstool still refers to him as Mario in the text at the end. Sad.
In the Game Boy Advance remake, Super Mario Advance 2: Super Mario World, Luigi is playable from the start, so no special tricks are needed. He also has a higher jump and is more "slippery" unlike the original Super Mario World.