Syphon Filter: The Omega Strain is the fourth installment of the Syphon Filter franchise, and the first one to be released on the PlayStation 2 system. Instead of playing as Gabe Logan, the exiled agent from the top secret Agency, players will create their own character, which is a new recruit for the Agency.
Following the destruction of the first Syphon Filter virus, the Agency has received a new cover as the International Presidential Consulting Agency, dedicated to battling terrorist enemies. Gabe Logan, as Commander-in-Chief, has hand-picked a team of leaders and agents for his new organization, including Lian, Teresa, Mujari, Dr. E, and more.
The past returns when Syphon Filter reemerges as the deadlier Omega Strain. A Chechen officer named Mikhas Ivankov is selling it on the black market, and outbreaks are occurring around the world. The man behind the conspiracy, Mihai Niculescu, sends Mara Aramov to find and eliminate him. Meanwhile, Gabe and the Agency split up and investigate locations of certain outbreaks.
An Agency team headed by Imani Gray visits Carthage, Michigan in search of Mujari, who disappeared while investigating Dr. Richard Broussard. Broussard had made a deal to give the virus to terrorists from the Anarchiste Liberation Army, but he backed down. The ALA acquired it anyway, and attacked the city. Imani and her team rescue Mujari to find the Omega Strain has infected him. The agents defeat the ALA leaders: Andre Proust, Soren Masson and Jean Fournier, then prepare for their next assignment. Investigating an Ebola outbreak in Uganda with Lian, Gabe shows his obsession for stopping the Syphon Filter conspiracy.
IPCA commander Gary Stoneman tells the Agency operatives about his history as an assassin for the CIA, and how he recently killed mafia leader Dimitri Alexopoulous to keep him from obtaining the Omega Strain in Italy. The team follows Stone to Belarus and tracks a shipment of infected cattle which leads to the residence of Ivankov. They discover that his courier Yuschenko is selling the Omega Strain, and Agency pilot Alima Haddad ends up captured by the Chechens. Stone assumes the worst, presuming she was killed.
Lian later tells the Agency team how she identified that North Koreans were attempting to purchase the virus. She infiltrated the domain of warlord Askar Saydahmat and found his people were about to give the Omega Strain to Sok-ju Yang, with a Yemeni terrorist being present as well. Lian eliminated all the involved parties.
Gabe enlists help from Ehud Ben Zohar of the Israeli Mossad upon determining that Yuschenko plans to sell the virus to Fatha Al-Hassan, a Yemeni leader. Zohar only cares about stopping the man's terrorist connections, so he steals the viral canister after the Agency retrieves it from Yuschenko, and uses it to force Gabe's people into helping his mission.
Zohar and the team enter Al-Hassan's palace disguised as the dead Chechens. After Zohar eliminates Al-Hassan, he searches for evidence of weapons contracts while the Agency personnel defends him. Stone arrives to rescue them, and reveals that Gabe sent him in case Zohar tried any tricks. They exchange the contracts for the virus.
Next, the team investigates a lead recovered from the Belarus operation that shows Dr. Nikolai Jandran is conducting virus tests. Maggie Powers assists them in breaking into Jandran's labs and recording evidence. The team escapes before enemy forces destroy the university where Jandran works.
Mujari, having recovered from the virus, explains his own investigation into the Chechens and why Ivankov wants independence from Russia. He sees that Uri Gregorov and other Russians are imprisoning the rebels, and finds hints of atrocities. Mujari knows both sides have reasons for what they do, thus the situation is not black and white.
Afterwards, Mujari takes control of the Agency team as they check the wreckage of the S.S. Lorelei. The university turned up salvaged boxes, indicating an undersea operation. Mujari requires that his team incapacitate innocent guards, and he evacuates the salvage rig before the Agency's planted nukes destroy the viral containers for good. However, Jandran dies from a serum before he can be brought back for questioning.
While Gabe faces pressure from the president and Alex Birchim of the White House Internal Affairs, he sends Lian and the team to track North Korean agent Yong-jun Kim, a man connected to Murakawa Industries in Japan. The investigation reveals that Murakawa, a part of the Yakuza, was helping to develop the Omega Strain. Aramov arrived before Lian and forced Murakawa to commit suicide for trusting Kim. Kim pretended to work with Murakawa so he could get the virus.
Unfortunately, the team hears tragic news after destroying the Japanese labs. Imani had been tracking Kim on an airplane that crashed in Myanmar. Out of guilt, Lian takes the team to recover her body and the viral sample Kim was carrying. Despite claims that inclement weather brought down the jet, they find evidence indicating that Aramov had paid the Myanmar army to shoot down the plane.
Gabe becomes frustrated with his investigation into the secret corporation Meta Global Funds, which he believes controls the Syphon Filter conspiracy. The purchase of Murakawa Industries by Meta Global was possible through Niculescu Funds, headed by international banker Mihai Niculescu. He is powerful and influential, but secretive as well, so Gabe suspects he is behind Syphon Filter. Against Birchim's commands, Gabe brings the Agency team to storm the Niculescu Funds headquarters in Zurich. They break in and find evidence linking Birchim to bribes, but nothing implicating Niculescu.
Gabe will later describe the rest of his investigation to the Agency team, and how he looked into Niculescu's Montenegro estate in a final effort to expose him. Although he did not find physical evidence, he learned that Mara was working for him, but Mihai betrayed her. Mara did not want Ivankov to destroy Moscow, for he traded the Omega Strain to the North Koreans for a nuclear weapon.
Having learned of Ivankov's location from Mara, the Agency mobilises to his base and works to prevent the missile's launch. Stone recovers Alima, injured but alive, and the team works with Gabe to disable the nuclear weapon. Ivankov is eventually killed during a fight with Gabe when the enemy attempts to escape through the forest.
Depending on the player's actions, the base is destroyed and the missile launch is prevented, or the nuke detonates in the ocean. However, cutscenes that play show these definite scenarios:
- Dr. E and Mujari cure the Omega Strain and destroy the final traces of Syphon Filter.
- Criminals eliminate Niculescu after an Agency computer virus erases the money of his illegal clients.
- Government officials arrest Birchim after Gabe shows the President files linking Birchim to bribes.
- The conspiracy is over, and Gabe can focus on other threats.
- Dr. E resigns from the Agency, confessing that she had met Mihai Niculescu before and had a romantic relationship with him.
- She intended to kill Jandran as well, believing that her destiny is to change the world.
- Elsa exits from the Agency base, and Gabe wonders what will happen next.
- A view of Stone's scope zooming in on Aramov speculates that the former is sent to assassinate the latter in the next game.
- IPCA European Command: Training Centre
- Carthage, Michigan: Quarantine Zone
- Carthage, Michigan: Warehouse District
- Carthage, Michigan: Carthage Mall
- Bonus mission 1 - Pescara, Italy: St Cetteo's Square
- Mazyr, Belarus: Krivorozhstal Mill
- Mazyr, Belarus: Belaya Vezha
- Bonus mission 2 - Tash, Kumyr, Kyrgysztan: Saydahmat's Village
- Sana'a, Yemen: Arms Bazaar
- Sana'a, Yemen: Taherir Palace
- Minsk, Belarus: International University
- Bonus mission 3 - Samaschki, Chechnya: Ivankov's Home
- North Atlantic: Lorelei Salvage Rig
- Tokyo, Japan: Murakawa Tower
- Taguang, Myanmar: Irawaddy Basin
- Zurich, Switzerland: Niculescu Funds Tower
- Bonus mission 4 - Budva, Montenegro: Niculescu's Villa Estate
- Kiev, Ukraine: Chechen Terrorist Base
All the bonus missions are unlocked by completing the previous "episode" within the time limit.
- Italy is unlocked by completing Carthage 1, 2 and 3 in solo par.
- Kyrgystan is unlocked by completing Belarus 1 and 2 in solo par.
- Chechnya is unlocked by completing Yemen 1, 2 and Minsk, in solo par.
- Montenegro is unlocked by completing the Lorelei salvage rig, Tokyo, Myanmar and Zurich in solo par.
- First Syphon Filter game where Gabe is seen on the cover page, but not generally playable.
- Each cutscene in the game begins with a strange green glow on the screen.
- First game in the series that was designed for the PS2 rather than the PS1.
- Although it can be purchased on the American PS store, it is strangely absent from the European and Japanese stores. This also means that Australia, Japan, the UK and certain countries in the UK will not have the game. This is because Australia's PS store has the same content as the European store.
- Montenegro is the only bonus mission where the player can lose stealth without triggering an automatic restart.
- Somehow, the SMAW does not damage the tank in Belarus 2, and only anti-armour frag grenades will destroy it. It is strange that Stone would use such a weapon to distract it.
- The SMAW can be seen being used by a Japanese goon in Tokyo, but the player can find no such weapon on the rooftop. It is also presumably used to down the jet carrying Imani Grey and Yong-jun Kim, yet the weapon is never actually found in Myanmar.
- It is strange that only Imani Grey's and Yong jun Kim's bodies are found inside the Myanmar rainforest, given the fact that hundreds were killed in the plane crash.
- The founder of Sony Bend is Mark Blank - He is the genius behind the classic text adventure, "Zork."
- A triple head-shot is possible - and by extension, anything beyond that can theoretically be done.
- If a stage is completed offline, players can access the next mission online, and vice versa. The only exceptions to this are the bonus levels which are unlocked by obtaining par times for a certain "episode", and the Lorelei salvage rig, which is unlocked by completing Minsk.
- The highest rank attainable playing only offline is C6, and only online, C1.
- In multiplayer games, the host can kick others out using the options menu from the pause screen.
- Only Syphon Filter game that requires players to work together during online games. In the other games, players can engage in competitive multiplayer. Both cooperative and competitive play would return in the next games Combat Ops, Dark Mirror and Logan's Shadow.
- This is so far the only Syphon Filter game in which dying will in no way whatsoever affect the mission, which can continue, although the player will need to try the mission again in order to achieve no deaths. However, the bonus missions follow the same convention as the trilogy, so getting killed will restart the mission.
- This is by far the first and only Syphon Filter game which introduced the concept of par times, in which missions must be completed within a time limit.
- It is the first game to introduce Gary Stoneman as a playable character.
- This was initially developed as a game that only had online multiplayer but Sony required offline missions to be available. Bend had to rush things which might have caused players to play later missions in order to unlock better weapons that gave them the edge to meet par time requirements, thus allowing bonus mission to be unlocked. For example, players would complete the Belarus missions before replaying those set in Carthage, which would then unlock Italy.
- Jennifer Hale played Naomi Hunter and Emma Emmerich from Metal Gear Solid and MGS2 respectively, before voicing Mara in this game. Both Naomi and Emma are love interests for Otacon, both also getting killed during the games.
- Paul Eiding, Kim Mai Guest, Khary Payton and Jennifer Hale have all four voiced characters from the Metal Gear Solid series, while also being involved in the Ben 10 franchise.
- Eiding played Colonel Roy Campbell in addition to Gary Stoneman.
- Kim played Mei Ling in addition to Lian Xing.
- Khary Payton played Drebin 893 in addition to Lawrence Mujari.
- Jennifer Hale played Naomi Hunter and Emma Emmerich in addition to Mara Aramov and Maggie Powers.
- It is actually possible to fail a mission, but still get 0 deaths. The trick to doing this is knowing which objectives exactly will contribute to the mission completion. For example, the player only has to complete, or fail, two objectives in Ukraine: neutralise Ivankov's lieutenants and protect Gabe. However, since Gabe is invincible whether or not the player provides cover for him, you can simply trigger the missile countdown timer and then wait around, allowing Logan to proceed with the mission but also letting your character hang back to avoid combat.
- It also introduced a number of conventions that carried over to Dark Mirror and Logan's Shadow:
- Dead enemies will 'turn' into boxes rather than actual corpses.
- Players are limited to five weapons at the most at any one time unlike the trilogy.
- There is an equipment selection menu before every mission.
- Ratings significantly increased the replay value.
- Stone was clearly seen aiming at Mara, who is alone on her safehouse balcony, during the post-credits cutscene. Yet in Dark Mirror, he sees her inside the house, and she is arguing with Elsa Weissenger, who was absent from The Omega Strain's version of this event.
- Furthermore, why on earth would Mara have bodyguards (in Dark Mirror) when they were also absent (in The Omega Strain)?
- Despite being armed with a sniper rifle and taser when he raids Niculescu's house, Gabe is somehow seen with a pistol when the mission's concluding sequence plays, apparently preferring to threaten Mara with a handgun rather than a more powerful weapon despite his numerous attempts to kill her in the prior games being foiled by her apparent immortal tendencies.
- The Spectre can only carry 30 rounds per magazine in gameplay but the equipment description claims each cartridge can contain 50 bullets.
- The briefing for Tokyo, Japan: Murukawa Tower claims that Lian's rank is a AOC, but that of Taguang, Myanmar: Irawaddy Basin has her as a COO. The latter is correct (Chief of Operations), since the AOC (Assistant Operations Chief) is Teresa Lipan.
- Furthermore, the AOC should be ACO.
- The M16A1 does not have any visible suppressor, but the sound it generates is that of a silenced weapon. In fact, it should not have such little noise.
- The Chinese type 67 presented in-game is a nightmarish version as compared to its actual real-life derivative. Firstly, the weapon's callsign refers to a light machine gun. It is silenced in reality, yet its sound is that of a non-suppressed weapon (the exact contrary of the above M16A1 example). It can somehow replenish rounds from a Soviet weapon, despite firing 'subsonic' bullets. Furthermore, it would have 30 rounds in each magazine, but can only hold 12 bullets in the game.
- The M16-K suffers from a myriad of issues, as with the above example quoting the Chinese type 67.
- Firstly, despite being listed with a magazine capacity of 30 rounds (which corresponds with the magazine shown on the weapon model), the equipment description is blatantly ridiculous.
- It is declared to be some sort of "submachine gun", the game then proclaims it is a "modified M-16" which is a contradicting statement.
- It is capable of firing "45 Glazer rounds" even though it apparently has a standard STANAG magazine.
- True to the description of being a submachine gun, its firing rate is fully automatic; however, it inexplicably possess a sniper rifle's variable zoom sight (or, at the very least, the developers attempt to permit the players use of such an aiming instrument).
- Somehow, despite its bullet archetype and zoom scope, it is also mind-bogglingly ineffective at long range combat, perhaps again reflecting the claim that it is simply a submachine gun (though its design could deceive inexperienced users to believe it is a long-range weapon).
- The idea of a SMAW being able to destroy, let alone damage, a main battle tank, while entertaining and hilarious for gameplay purposes, is totally nonsensical in reality. Equipped with extremely heavy armour on the front and sides, such a vehicle would require a flanking attack from the rear to even inflict sufficient devastation to decommission it, and that is assuming the offensive party is not affected by its numerous weapon systems, and, indeed, the infantry escorts that would naturally accompany this into combat. Furthermore, while tanks are, at least to some degree, weak against rearward assaults, their top is totally unprotected, and Stone would have needed a Javelin missile launcher, which employs a top-down attack pattern (exploiting such a weakness by taking advantage of gravity), to destroy the vehicle in real life.
- The Carthage missions were rather out of place because they were originally supposed to be set in Toronto. Canada officials weren't happy with that idea, so it was switched to Michigan - but the city doesn't exist. There is a Carthage in the nearby state of Illinois, but not in Michigan.
- In truth, Michigan does not have any subway systems.
- In the rewards section of the main menu, players can earn commendations by completing objectives in a mission or the missions commanded by a certain character. It is thus possible to earn the commendation for Zurich by completing all the objectives in this mission. The commendation earned in this manner is Teresa Lipan's, but it should be Gabe's commendation rather than Teresa's because Logan was integral to this particular mission.
- When you look at the Statistics screen, "Mazyr, Belarus: Krivorozhstal Mill" and "Mazyr, Belarus: Belaya Vezha" are shortened to "Belarus 1" and "Belarus 2", respectively. However, a later mission that takes place in a different area of the country (Minsk, Belarus) is shortened to "Minsk". This should have been shortened to "Belarus 3".
- Fadhil's fate is left unresolved; the player encounters him in the arms bazaar in Yemen, and may choose to kill him, but he is never seen outside of this mission.
- Why would Mujari use an Advanced Combat Rifle during the mission on the Lorelei salvage rig if he claims to only kill in self-defense? (A similar issue is raised in Syphon Filter 3's Africa missions, where he conducts a killing spree despite having a deep personal aversion to violence).
- This question is answered in the mission briefing. Mujari states that "I am a pacifist, but I am also a realist." Mujari goes on to express his desire not to kill, but his willingness to, if need be.
- On a similar note, why would Gabe bring a lethal sniper rifle to investigate Niculescu's estate if he claimed he would not kill enemies until he knew the art collector was behind the entire Syphon Filter conspiracy?
- It should be noted that the player can choose to knock out nearly all of the mercenaries although Gabe is forced to use his rifle against Mara's two guards to avert her execution.
- Jump glitch: Allows certain online objectives to be completed without requiring team members.
- Armour glitch: Player can acquire a 10,000-point flak jacket.
- Magic box glitch: Allows players to acquire potentially any desired weapon
- Grenade multiplier glitch: Players can rake in an inordinate amount of grenade kills.