Crushing Difficulty
Description: Unlock a difficulty harder than Hard Mode (called "Crushing")
How to unlock: You have to complete the entire game, all chapters, on Hard Mode without once changing the difficulty level. If you do this successfully, you should be able to select Crushing difficulty during your next playthrough.

Drakes Jersey
How to unlock: head to the Costume section of the game and insert the following code:
Left, Right, Down, Up, Triangle, R1, L1, Square.

Making A Cutscene Secret Videos
Description: To unlock secret videos embedded in the Making a Cutscene section of the game, insert the following codes:

Video for Grave Robbing	Left, R2, Right, Up, L2, Triangle, Square, Down
Video for Times Up	L1, Right, Square, Down, Left, Triangle, R1, Up

Concept Art Secrets
Description: To unlock secrets embedded in the Concept Art, head to the Rewards section of the game and insert the following codes:

Video	L2, Right, Up, Square, Left, Triangle, R1, Down
More Art	Square, L1, Right, Left, Down, R2, Triangle, Up