Unlock Professional and Continuous Mission Mode:
Beat every EX mission to unlock Professional (no target alerts) and Continuous (no dialogue) mission modes in the EX options.
Unlock Real-Time Window:
Get a grade of S or better in the Shooting Range to unlock the Real-Time Window. Turn it on in EX Options. This places and locks the scope view in the upper-Left corner of the screen.
Free health:
Shoot about five or more people in the head.
Defeating Bosses:
To easily kill a Boss, shoot him in the head.
Secret level:
After completing all the levels there will be a final confrontation level. You will have to get to a swordsman Boss and defeat him. He will come at you with his sword. Shoot him then. After that, you will have to find your way to a 1-shot Boss. To kill him easily, wait for the shuttle to stop moving, then make your shot. After that, you will have to kill your own Boss.
Extra Contact:
If you stare at Life-up Girls, Robert or your partner will say 'How long are you going to stare like that?' or 'Am I in your view?'. This will not work on the 4WD or by Helicopter on the train level.
Kissing Bosses:
Successfully complete consecutive mode on Silent Scope EX and the Phantom and the Prince Of Rose will kiss each other.