If tu want to know how to be Luigi I will tell you. First tu finish the game than tu go to to the perfil menu and tu hold l and R as tu open tu perfil and tu will see Luigi. If tu save when tu play as Luigi it won't work so tu have keep on holding l and R everytime tu want to be Luigi and to be Mario just do not hold l and R just do what tu always do just go on. I hope this works for tu because it works for me. THIS IS ONLY FOR NEW SUPER MARIO BROS AND NEW SUPER MARIO BROS 2 NOT ANY OTHER GAME.