is a Japanese role-playing video game developed by Feelplus and planned by Mistwalker for the Xbox 360. It was published by Microsoft Game Studios in 2007 in Japan and 2008 in western territories. The story follows Kaim, one of a select group of "immortals" who have lost their memories: while confronting threats generated by the world's approaching magical industrial revolution, he must also face the pain brought by his returning memories. The gameplay features many staples of the genre, such as navigation using a world map, random encounters, and a turn-based battle system.

First discussions surrounding Lost Odyssey began in 2003, with development beginning the following year as an internal Microsoft project. After running into difficulties, Feelplus was established as a dedicated studio to work on the game. The story was written by Hironobu Sakaguchi and Japanese author Kiyoshi Shigematsu: Sakaguchi wanted to create a story focusing on evoking human emotions, and kept the gameplay within genre traditions so he could experiment with the story. The game went through a difficult development, with problems stemming from the chosen engine technology and the arrangement of development teams. The music was composed by Nobuo Uematsu, a veteran composer for the Final Fantasy series.

Lost Odyssey

First hinted at in 2005, the game was officially revealed shortly before that year's Electronic Entertainment Expo. At the time it was released, it was Microsoft's largest console game, spanning four dual-layer DVDs. Upon its debut in Japan, it sold favourably, eventually selling nearly 110,000 units by April 2010. It also received strong sales overseas. Its critical reception has been generally positive: while praise has focused on its story, many journalists were critical of its traditional design and loading times.

Lost Odyssey

Gameplay

Lost Odyssey uses a traditional turn-based battle system seen in most Japanese role-playing games, similar to early Final Fantasy iterations. A world map allows the player to move the party between adjacent towns or fields on the map, while later in the game the player is given more freedom to explore the world through the use of ocean-going ships. Towns and cities provide inns for the player to read the thousand years of dreams, Mana/HP recovery orb for health and mana, stores for buying and selling of equipment, and save points for the game. While exploring certain areas, the player will randomly encounter monsters to fight.

Lost Odyssey

The combat system incorporates aspects of battle initiative and length of actions to determine how events resolve each turn. Item usage is instantaneous, regular melee attacks are executed on the same turn, while casting spells or using special abilities may delay the player's action for one or more turns, depending on their speed. Actions can be delayed if the user is hit by an attack. The player has the option to cancel an action on a subsequent turn if necessary.

Melee attacks include an "Aim Ring System" using equippable rings with added effects. As the character launches the attack, two concentric targeting rings appear on screen. The player must time their button release in order to make the rings intersect. An accuracy rank ("Perfect", "Good" or "Bad") indicates the potency of the effect. These include additional damage specific to certain types of monsters or their magic element, hit point or mana absorption, status ailments, or being able to steal items. Even if awarded a "Perfect", the character can still miss the attack altogether. These rings are created by synthesizing "components", and can be upgraded into more accurate, or more potent versions; advanced rings can be made by combining two or more rings at a special vendor.

In combat, both the player's party and enemies are arranged in two lines, front or back. Up to five party members can participate in battle at once. At the start of battle, the back line is protected by a special defensive "wall" which is based on the combined hit points of the front line. This wall reduces damage that the characters in the back experience. However, as the front line takes damage, the wall weakens, and can only be recovered through the use of certain spells or skills.