Big Boss returns to battle in this all-new MGS action game for the PSP system. Set in 1970, the game acts as a missing link in the ongoing Metal Gear Solid narrative, as players learn more about returning characters such as Para-Medic, Major Zero and Sigint and also witness Big Boss' greatest tragedy -- one that sets into motion the events of later games in the series' timeline. Portable Ops introduces a new team building mechanic that brings additional depth and gameplay variety to the series -- players can now capture and recruit characters and train them to be part of their army to help Snake on his mission! The game also features fully-voiced cut scenes with original artwork by acclaimed visualist Ashley Wood.

In addition to a full-fledged single player mode set after the events of MGS3: Snake Eater, the game's multiplayer modes let players take their custom squad online to do battle across new levels, featuring a unique "White Flag" mechanic that will allow players to fight to the death (with your valuable squad on the line if you lose) or surrender to compete again.