Beat the following modes in order "Training", "Time Trial", "Gun Shooting",
"Survival". Note:
Completing each mode will unlock the next mode in the sequence. Then,
"Technical demonstration"
mode will be unlocked. Use it to watch the CPU demonstrate its best
time with the gun.
Alternate costume
Beat the game two times using the same saved game location, and getting
a different ending both
times. Then, Snake will change into a tuxedo in the elevator during
the next (third) time the game is
played. Beat the game once more, and get a different ending. Then,
Snake will change into a ninja
costume during the next (fourth) time the game is played.
Alternate title screen
At the title screen, press the D-pad to change the background color.
Konami game surprise
Play the game using a memory card that contains a saved game from any
prior Konami title
(Castlevania, ISS Soccer, Suikoden, Silent Hill etc.) Then, when Psycho
Mantis attempts to read
your character's mind, he will mention various game titles.
Hint: Defeating Psycho Mantis
Plug the controller into port two and press any button before fighting
Psycho Mantis. The word
"Hideo" will appear in the corner of a black screen. Use controller
two to fight against Mantis to
keep him from knowing your moves.