Perfect Ninja Painter

On the Second Level of each location there is a secret map that you can collect which unlock all levels in the current location.

Below is a text guide for unlocking all levels in each location by collecting the secret map.

Unlock All Village Levels
Village: Level 2
DDDR -

Unlock All Town Levels
Town: Level 2
LUDLU -

Unlock All Metropolis Levels
Metropolis: Level 2
DLULL -

Unlock All Elite Village Levels
Elite Village: Level 2
RRDD -

Unlock All Space City Levels
Space City: Level 2
LURUL - L