R2, L2, Up, Down, Square, Triangle, Circle on Main menu
Level Complete
R2, L2, Up, Down, X, L3, Circle, X, Circle, X
Megaforce
R2, L2, Up, Down, X, R2, R2
Mission Select
Quickly press R2, L2, Up, Down, Square, Triangle, Circle at the main menu
Nailgun Mode
R2, L2, Up, Down, X, L1, L1
Punch Mode
R2, L2, Up, Down, X, Up, Up
Slow Motion
R2, L2, Up, Down, X, Up, L2
Unlockables
Get a Sawed-Off Shotgun - You will receive the ''Sawed Off Shotgun'' after gaining 'Silent Assassin' ranking for the second time in the game. This must be on a mission which you haven't received the ranking before.
Get An M4 - Earn a Silent Assasin ranking on all of the St. Petersburg missions up to and including ''Invitation to a Party'' without any aggression. Pass ''Invitation to a Party'' last and you will recieve the M4.
Getting Silenced Ballers - You will receive ''Silenced Ballers'' after gaining 'Silent Assassin' ranking for the first time in the game.