To get a different background color press down on the left and right buttons on the D pad. It worked for me, i dono if it will work for u tho, so good luck!
To unlock the Secret Pictures, beat every mission in the entire game.
if a terrorist is coming your way and there is a wall that is blocking the terrorist's view run up to the wall and you will see your hiding now if you want to confuse the terrorist press 0 whilst hiding then you will knock on the wall the terrorist will come to the place you knocked so hide another place then when he walks away you can strangle and kill by pressing square (without pressing a directional button if you do it will trip him over then he'll chase after you) and repeat pressing square to kill the terrorist or shoot him with any gun also you can throw any sort of grenade you can use a stun grenade you affect the terrorist's view or any other grenade exept for a chaff grenade use that if you are fighting vulcan ravan with his tank or for survalence cameras.
To unlock the Mei Ling photo shoot, beat all the sneaking modes with a best time (30 in all).
To unlock Mystery Mode, complete 70% of the total missions.
To unlock NG Selection Mode, complete at least 80% of the VR missions.
To unlock Ninja Mode, complete 85% of the total missions.
To unlock Puzzle Mode, complete at least 50% of the VR missions.
at the Start screen hold R1 and press:
,O,X,/\,Select and L2 to play as the Cyborg Ninja!