Successfully complete all EX missions to unlock the "Continuous Mission Mode" option at the "EX Options" menu.
Defeating Bosses
To easily kill a Boss, shoot them in the head.
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.
Hint: Free health
Shoot about five or more people in the head.
Kissing Bosses
Successfully complete consecutive mode on Silent Scope EX and the Phantom and the Prince Of Rose will kiss each other.
Professional mode
Successfully complete all EX missions to unlock the "Professional Mode" option at the "EX Options" menu.
Real-time window option
Complete the indoor shooting range with a "S" or better rank to unlock the "Real-time Window" option at the "EX Options" menu.
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.
Teddy kill
In Silent Scope EX, you will encounter a helicopter Boss. He will have an afro and a teddy bear in the front seat. Shoot the teddy bear in the head and the helicopter will crash.