Highlight the "New Game" option at the main menu.Then,hold Square+Circle+L1+R2+Select+Up+X.
SUPER AGENT MODE:
Pause game play and highlight the "Weaponry" option.Then hold SELECT+L2+CIRCLE+SQUARE+X(In that order).A sound will confirm correct code entry.Enter the options screen and select "Cheats".Super Agent Mode allows enemies that have flak jackets to be killed with a single shot.
Pause game play and highlight the "Map" option.Then hold RIGHT+L2+R2+CIRCLE+SQUARE+X.A sound will confirm correct code entry.Enter the options screen and select "Cheats".This allows the current mission to be successfully completed.
Pause game play and highlight the "Briefing" option. Then, hold Right + L1 + R2 + Circle + X. A sound will confirm correct code entry. Enter the options screen and select "Cheats". Alternately, successfully complete the game to unlock all but four of the game's movies. The final four movies are unlocked when the game is successfully completed under the hard difficulty setting.
The first bonus movie is unlocked after Mission 5 (McKenzie Airbase Exterior) under the hard difficulty setting. Lian will say "Got it" as she is flying away in the helicopter to confirm the secret. The movie is called "Before and After I" and is on disc 1. It has some behind-the-scenes footage of an early rendition of Gabe. It contains CG footage of Gabe running through the missile silo from the first Syphon Filter. Gabe does not look very detailed and the silo looks completely different. Then the movie transitions to the finished version we saw in the game, with Gabe confronting Markinson.
The second bonus movie is unlocked after Mission 10 (Morgan) under the hard difficulty setting. Gabe will say "Got it" after he finishes receiving the incoming radio call. The movie is called "Before and After II" and is on Disc 1. It has some behind-the-scenes footage of a later version of Gabe and an early version of Lian. It shows Gabe and Lian sneaking through the Costa Rican rain forest from the opening movie of the first Syphon Filter. Gabe has a gray short-sleeved shirt on and camouflage pants and Lian is dressed in a black tank top and camouflage pants -- she kind of looks like Lara Croft without the ponytail. Then, the movie transitions to the finished version we saw in the game, with Gabe and Lian sneaking through the forest and coming across the burnt out lab.
The Third bonus movie is unlocked after Mission 16 (Aljir Prison Escape) under the hard difficulty setting. Lian will say "Got it" after she and Gregorov reach the escape point. The movie is called "Deleted Scenes" and is on Disc 2. It has four FMV clips that were not used in the game. The first one shows the Chinese general demanding shipment of the Syphon Filter virus. The second shows Archer in the Blackhawk swooping low over Gabe, who is on the back of the burning United Pacific train. The third shows Gabe and Teresa in the beat-up rental van they use during the Moscow missions (where Lian is chasing Gregorov) -- the van will not start and Gabe gets out to push. The fourth shows a bag lady pushing a shopping cart across the street in the New York Slums district -- Mara Aramov's limousine smashes the shopping cart and then screeches around a corner.
The fourth bonus movie is unlocked after completing the game under the hard difficulty setting. The movie is called "Congratulations! Party time!" and is on Disc 2. It is kind of amusing, and shows all the major characters dancing on the floor of the Moscow disco, Club 32.
AGENCY COMPUTER LAB MULTI-PLAYER STAGE:
In the second room at the start of the Agency Bio-Lab Escape level, (after receiving the incoming radio traffic) are two vents that you can crawl through. The one on the left is the correct exit out of the Bio-Lab. The other vent leads back the way you came toward the Operating Room where you overheard Dr. Weissinger in the previous level. Head down this second vent back the way that you came from. When you exit the vent, there will be one Unit 1 trooper on the left in an alcove. Run past him down the U-shaped hallway which leads to the Operating Room. You should be able to see the autopsy table through the door. There are three more armored troopers in the operating theater -- one low by the door and two on either side up in the theater seats. Roll into the room past the low trooper. If this is not done, when you get near the door he will run in front of it to block your path. Run immediately toward the table with the computer. Climb up on to the table, and then up onto the balcony (you will probably get shot up pretty bad while climbing up). Then, roll toward the center of the back wall and into a small room. There is an M-79 grenade launcher in this little room which unlocks the Agency Computer Lab map. Gabe will say "Got it" to confirm that it has been collected. You do not have to finish the level for the map to be unlocked.
BUNKER MULTI-PLAYER STAGE:
Find the PK-102 in the Moscow Streets level. There is a point where two cars will try to run you over at the same time, and you have to leap and grab a pole above you to avoid them. After this happens, drop down, and go back and search the two newly crashed cars. Face the tail ends of the cars. The car on the right has the PK-102 inside. Warning: The cars are on fire, so search carefully. Also, after they crash an enemy will get out of each car. At least one of them has a M-79 grenade launcher.
CAVES MULTI-PLAYER STAGE:
Find the binoculars in the Colorado Interstate 70 level you must find the Binoculars. They are located behind the first closed door on your left that you reach. Press Triangle to open the door. This reveals a passage. Go left, open another door, and enter the room. The box containing the binoculars is in this room.
D.C. CITY PARK MULTI-PLAYER STAGE:
Find the dirty laundry in the New York City Slums District level in one of the washing machines in the first Sniper Building of the level. This is the building that is similar to the slums district level in multi-player mode.
While in the flaming building in New York City, you should come across a set of laundry machines. Run to the last one closet to the wall, and the words "Dirty Laundry" will appear. Press Action, and you will put a coin in the machine followed by a loud "Yes I Got It!".
DISCO UNDERGROUND MULTI-PLAYER STAGE:
In the Disco 32 level, after killing the bodyguard on the catwalk, three more guards will run in the door. Kill all three before they can throw a grenade at you. None of them have flak jackets.
JUNGLE MULTI-PLAYER STAGE:
Kill Archer at the very end of the C-130 Crash Site level with one shot (head shot). It is recommended that you use the silenced sniper rifle to kill him because of its zooming capabilities.
PHARCOM INCUBATOR LAB MULTI-PLAYER STAGE:
Find the girlie mag in the Pharcon Lab, after you taze the guards. It is located after you go through the Mars exhibit.
PRISON MULTI-PLAYER STAGE:
Complete the Aljir prison break in without using the crossbow. You will have to sneak and roll up to the first man before he makes it out in the open. Roll a lot, but do not roll into him. You also cannot run or he will turn around. You should be able to run up very close to the male guard and the female guard who chased down the second prisoner. The last guard turns and looks around quite a bit. Walk against the left wall, and hide behind the support. He will walk out past you, and then you can get him.
ROCKIES MULTI-PLAYER STAGE:
Find the H11 sniper rifle on the first level (Colorado Rockies). The H11 is near the waterfall and ice arch where you first meet Chance. Instead of jumping over the waterfall chasm, hang from the edge of the chasm and drop down into the tunnel. The H11 is in there.
SURREAL MULTI-PLAYER STAGE:
In Volkov Park, kill the first guard to the left very quickly before he destroys the car. After you kill him, collect the BIZ-2 in the car he did not destroy.
ADDITIONNAL MULTI-PLAYER CHARACTERS:
Find the M-79 grenade launcher on the second to last level (New York Sewers) to unlock the following seven multi-player characters: Ninja Gabe, Scuba Lian, Unit 1 (the final Boss), Dr. Elsa Weissinger, Uri Gregorov, Lawrence Mujari, and SWAT officer (helped in the New York Slums level). The M-79 is near the end of the level (in the parking garage). Near the top of the stairs is an open doorway into the parking garage, where a black van is driving past. Instead of exiting the stairwell at that location, keep climbing up the stairs. There will be five Agency operatives scattered on the landings above armed with silenced HK-5s, grenades, and M-79s. Use the M-79 to clear them out. The M-79 is on the top landing.
Complete the C-130 Crash Site level under three minutes to unlock the characters from the original Syphon Filter game in multi-player mode. The additional multi-player characters from the original Syphon Filter are: Girdeux, Phagan, Gabrek, Marcos, Rhoemer, and Evil Scientist.
To unlock the "goofies" set of characters (bag lady, CBDC agent, monk, corpse, and viral test subject), complete the McKenzie Airbase Interior level in under 3 minutes.