Star Ocean: The Last Hope is a single-player, role-playing game released exclusively for the Xbox360 system. The PlayStation 3 version, Star Ocean: The Last Hope International, released one year later, is a different game because of its additional content and features, although it shares the story.

The story takes place prior to all other games in the series thus far - Stardate 0010. The opening video segment shows the Earth being bombarded by nuclear weapons during a world war. In the aftermath, survivors have been forced to live underground because the surface has become toxic. To save our species, a decision is made - a new homeland must be found for humanity. Space Reconnaissance Force teams are launched into the "star ocean" of outer space in four separate spaceships as mankind's "last hope".

The main character is Edge Maverick who starts out as a crew member but soon becomes captain of the SRF ship, the Calnus, which the player will control. The ship has different rooms for item creation crafting, "Private Action" between characters, or picking the next travel destination.

Edge and his companions will visit more than six planets, explore towns and dungeons and meet alien races, both friendly and hostile. Some of the aliens will join Edge's party. There is exploration, character interaction, conversation and team-oriented combat in real-time. The numerous cut-scenes can be skipped if desired, and saving the game is only possible at designated spots on the map.

When a battle begins, the player can choose which character to control. Depending on the player's progress in the game, there can be as many as 8 characters travelling in the party, but only 4 can take part in combat. Each one of them has their own specific talents during battle. Some are better with melee attacks while others rely on shooting projectiles or on spellcasting. Fighting styles can be customized quickly to suit the particular battle with use of the new B.E.A.T. system (Battle Exalted Action Type). A variety of customizations are available including blindsiding enemies for guaranteed critical hits or equipping skills for an extra edge over opponents. There is also auto-targeting which can be manually changed if the wrong opponent is auto-selected.

The game uses an improved version of the game engine used in Infinite Undiscovery.

The North American release featured computer generated (CG) graphics with localized speech in English. Japan's version, however, had the more traditional anime graphics and contained Japanese speech and text.