Cheat mode
Press [Select], [Right], [Up], [Down],
[Circle], [Left], [Square], [Triangle], [Circle]
at the main menu to unlock the cheat options.
Hints
One hit kill with the knife
On level 1, when the man comes up, get your knife out.
Aim your knife at his head and throw it. This should kill him
silently. Do what you want to the other people. Remember to get
your knife back.