File Stars
To obtain all five file stars, you'll need to:
Beat the last Bowser
Find every normal and secret flag (there are 94 in all)
Catch Nabbit when he appears in each of the first seven worlds
Obtain every star coin in the standard 8 worlds
Obtain all star coins in every world and level, including level 9 in Superstar Road
Play as Nabbit in Single Player
To play as Nabbit on any stage in single player, hold down ZL when selecting a stage, and Nabbit will replace Luigi for that stage. Luigi will return after you finish the stage, or Nabbit dies in the stage.
File Stars...