Front Mission 2089 is a tactical role-playing game developed by Square Enix Co., Ltd., MSF, and Winds, and was published and released in Japan by Square Enix Co., Ltd. in 2005 and 2008 for the mobile phones. The game was released on March 7, 2005, October 27, 2005, and June 18, 2008. Front Mission 2089 borrows many of the gameplay mechanics found in Front Mission. The video game progresses in a linear manner: watch cut-scene events, complete missions, set up their wanzers during intermissions, and sortie for the next mission. Missions in Front Mission 2089 are traditional tactical RPG fare, ranging from destroying all enemy targets to protecting a particular allied target. Due to its mobile phone format, the story of Front Mission 2089 is told through episodic content; new episodes were released for download on the video game's official website on a bi-weekly basis. A returning feature in the game is the Arena. Like in Front Mission, players can fight other players to win monetary rewards. Mission rankings also make a return; based on the scoring system of Front Mission 3, players can earn new parts and wanzers by doing well during missions. Another returning feature is briefings. Lastly, players can choose to play two unique scenarios - one with the Oceania Cooperative Union (O. C. U. ), and one with the United States of the New Continent (U. S. N. ).

The plot of Front Mission 2089 revolves around a group of mercenaries led by Ernest J. Salinger. Given the codename "Storm", Ernest conducts sorties near Mail River. While many of the sorties involve basic reconnaissance and data collection, the mercenaries detect abnormalities by the border. Mercenaries hired by both sides begin mysteriously disappearing, and many of them were last sighted near Mail River. Unsure whether or not the mercenaries are deserting their duties or are truly disappearing, Storm's superior officer Falcon orders them to investigate these disappearances. During their investigations, Ernest and his group come across an unknown mercenary outfit known as the Vampires.