Metal Gear Solid: Portable Ops/Unlockables

There are many features that can be unlocked in the game.

Stealth Camo

In order to unlock the Stealth Camo, you need to attain a Tech level of 99.

Gameplay

Extreme Difficulty

In order to unlock the Extreme Difficulty, you need to beat the game once.

Boss Rush (EU only)

In order to unlock the Boss Rush mode, you need to beat the game once.

Characters

Name	Unlocking	Code (NA)	Code (EU)
Cunningham	Beat Cunningham on any difficulty by Stamina kill and beat the game before January 1st 1971.	JUNKER	CUN=BOA
Elisa		THE-L	E.WASP
EVA		E.APPLE	016K/HYH
Gako Soldier	He is only unlockable via Cheat Codes	!TRAUMER	GAK.O
Gene	(NA) Recruit a cumulative number of 200 soldiers on one save and beat Gene by Stamina kill. (EU) Complete Boss Rush mode.	ERBE	9-VIPER
NULL	Deplete either of his Health/Stamina bars in each fight, and complete the game.	Hunter-n	ALL=0
Ocelot	Recruit Sokolov, then head to the Silo Entrance and interrogate the Soviet Officer located on top of the bridge area. Wait until you receive a Spy Report from the Town. Head to the Town at nightfall and locate the Government Official in one of the upper buildings, then interrogate him. Head to the Airport and interrogate the FOX soldier at the control deck in order to learn a radio frequency: 141.23. Recruit EVA. Head to the Ravine and infiltrate its communication building. To do so, find the Key located on the second level of a nearby cave. Enter the building and contact the frequency (141.23). After the call, complete the game.	R.R.R.	THE-SON
Para-Medic	First retrieve the Malaria medication (story-based) and then head to the Comm Base, contact Para-Medic in the Comm room. She will arrive 3 days later (put spies in the Hospital to receive a report).	PM-EMS	E.M.S.
Python	Beat him by Stamina kill when confronting him.	LQ.N2	GUFO
Raikov	As soon as you discover the location of the Guest House, put spies in Town, if you already had spies in Town, you might have received the report Map Found, if not, do so and wait. You must do the mission associated with the report as soon as you receive it, or else you won't be able to recruit Raikov! When you have the report, head to the Town and locate the Secret Document in a building to the north. When it's done, place a spy in the Western Wilderness. When Snake is free from his prison, you will receive another report from Western Wilderness mentioning a "Handsome Soviet Major", go save him, you just need to reach the building in front of you when you start, then go down a ladder inside the room, then head down, his cell is opened.	IVN =RV	SKAZKA
Sigint		DARPA-1	D+ARPA
Sokolov		SATURNV	Vostok
Teliko	Have a Metal Gear Ac!d save on your memory stick, and start a new game on an already completed save.	T.F-ACID	SHINE!
Ursula		PK +ESP	ESP:ASP
Venus	Have a Metal Gear Ac!d 2 save on your memory stick, and start a new game on an already completed save.	MGA2VE	@VESPER
Zero	Have a Metal Gear Solid: Digital Novel save on your memory stick, and start a new game on an already completed save.	1+2-3	GALAXY-0