Hold C + Z and quickly press one of the following codes at the title screen.
Code: --- Result:
Left four times, Right four times, 1, 2 --- All missions and assignments
Up, Left, Down, Right, Up, Left, Down, Right two times, 1, 2 --- All normal items
Up, Right, Down, Left, Up, Right, Down, Left two times, 1, 2 --- All secret items
Up, Down, Up, Down, Left, Right, Left, Right two times, 1, 2 --- Full sword gauge
Down, Up, Down, Up, Right, Left, Right, Left two times, 1 --- Maximum items
Unlockables for Tenchu: Shadow Assassins:
Unlockable: --- How to Unlock:
Ancient Hissatsu Techniques --- Complete 30 Assignments
Colored Rice --- Obtain an S Rank on all 50 Assignments
Devil's Mask --- Get all 20 mask pieces in Shadow Mode.
Izayoi (Rikimaru's Unbreakable Sword) --- Get all of the map pieces in stages 1 through 5, and 10.
Memories (Video Gallery) --- Complete 40 Assignments
Ninja Tabi '08 --- Complete Story Mode
Onibi (Ayame's Unbreakable Sword) --- Get all of the map pieces in stages 6 through 9.
Sound and Music --- Complete 20 Assignments
Swing the Wiimote at the level selection screen. The screen will change colors and the Shadow mode level selection screen will appear. Shadow mode is more difficult with additional enemies and routes.
Acquiring S rank per mission in story mode unlocks 4 additional assignments. This unlocks all possible extra assignments per one mission in story mode. Obtaining A rank will grant 3 of the extra 4 assignments. Finally achieving B rank will give 2 of the 4 extra assignments.