Unlock all missions
On the mission selection map hold R1 and press
up, down, square, up, down, square, up, down, x. Release R1.
Unlock all videos
At the menu highlight the second choice.
Press L1, left, right, square, triangle, circle.
To choose hidden missions, find a mission on the map that has a shuriken beside it. Highlight the mission, then select it while pressing SELECT.
To play the boss with the second controller, hold the START button on the second controller before you select the mission. Keep holding it until the mission starts.
All cheats submitted by Reimaru