Getting the File Stars:
To get all of the game's File Stars, complete the steps below:
Defeat the final Bowser
Locate every normal and secret flag (94 in total)
Catch Nabbit once he appears each time on the first seven worlds
Get every star coin in the standard 8 worlds
Get ever star coin in every world and level, including level 9 on Superstar Road
Play as Nabbit in Single-Player:
To be able to play as Nabbit on any stage in Single-Player mode simply hold down ZL when selecting a stage. When you do this Nabbit will replace Luigi for that stage. When you then finish the stage or die Luigi will return.
Play as your Mii:
To be able to play as your Mii instead of Nabbit enter the secret Single-Player Nabbit code on the final Star Road level.