How do you unlock all levels in new super Mario bros wii

You can unlock all levels in NSMB wii in two ways:

1. You beat the levels and get to the secret places too.

2. For world 9, get all the star coins in one world to unlock one level. To unlock all 8, get all star coins in worlds 1-8. After you get all star coins for world 9, you've beaten the game to it's fullest extent, not including points and regular coins (which don't really matter).