The science fiction storyline, set across the Small and Large Magellanic Clouds, follows the life and growth of Yuri as he first confronts the aggressive expansion of the Lugovalian Empire, then a greater alien threat.

Infinite Space is a science fiction role-playing video game where players take on the role of protagonist Yuri, who leads a growing fleet of spaceships across different galaxies.

[7] Multiplayer spaceship battles are also available for two-players to play competitively over local Wi-Fi, selected from an option on the bridge of Yuri's ship and isolated from the main campaign.

[7] Infinite Space is set in the far future, where humanity has expanded beyond the Milky Way to colonise neighbouring galaxies including the Small and Large Magellanic Clouds (SMC and LMC), with travel between distant locations accomplished using Void Gates, constructs of an ancient civilization.

[11][12] A recurring feature of the setting are groups called Zero-G Dogs, who act as mercenaries fighting with different factions and are alternately admired and despised.

[13] The two major powers in the galaxies are the Galactic Federation, formed from nations across the SMC and LMC; and the Lugovalian Empire, controlling a quarter of the known universe and now expanding towards the Milky Way cluster under the guidance of Emperor Taranis.

[14][15] Other key characters encountered by Yuri are the notorious pirate Valantin; Cico, a Lugovalian who later becomes the Empire's crown prince; and Patriarch Bogd, leader of the Holy Nation of Adis.

Yuri and a growing crew of Zero-G Dogs go on the hunt for Valantin, ending up caught in the political struggles surrounding the aggressive expansion of the Lugovalian Empire into the SMC.

Yuri allies with the sympathetic nation Regeinland from the LMC, but their attempt to hold off the Lugovalian forces ends in failure forcing the Regeinland fleet to use a weapon to send a nearby sun into supernova, destroying all surrounding ships and the Void Gate connecting the two galaxies which prevents the Lugovalian fleet from quickly traveling to the LMC.

The Lugovalian Empire finds a new Void Gate and restarts their invasion of the LMC, causing civil conflict between Federation factions over their response.

Arriving to exact retribution, Yuri encounters Bogd and learns that the disappearances are caused by the Overlords, a god-like species who gifted humanity with their technology and have been repeatedly destroying and recreating the universe.

Yuri is revealed to be an artificial human called an Observer created by the Overlords, explaining his possession of an Epitaph and power over Flux Sectors, with Kira being a Tracker android sent to monitor him.

Yuri learns that the only way to stop the Phages is destroying the one Void Gate that links to the Overlords' realm, located in the original Solar System.

[23] Similar to Steel Battalion, Kono proposed a dedicated control peripheral for Infinite Space, but PlatinumGames rejected the idea in favor of having the broadest market appeal possible.

[17] The customization options also allowed players to complete a game with their "ideal fleet" rather than needing to acquire and upgrade different ships across the campaign.

[3] The difficulty curve was not intentionally high, but it was intended that players should learn the systems, and it served as an extension of the narrative featuring an inexperienced youngster going against ruthless veterans.

In addition, Kono designed the narrative to have a grand scope by using locations across multiple galaxies, contrasting against a trend he noticed for recent science fiction to stay within the Solar System.

[27][28] The ship, mechanical and environmental designs were handled by Kazutaka Miyatake of Studio Nue, Yasushi Yamaguchi, Junji Okubo, Tetsuyaro Shinkaida, Naohiro Washio, Goro Murata, and Mitsuru Yaku.

[31] It was commissioned by Sega at Inaba's request as he wanted to further express the world of Infinite Space, but knew the DS lacked the hardware to incorporate multiple anime cutscenes.

[33] Kono requested tracks that would express the expansive nature of space, something which proved challenging due to the DS's limited sound capacities.

[36] The soundtrack release included an orchestral piece titled "Infinite Space", created by Masamichi Amano and performed by the Tokyo Symphony Orchestra for the promotional anime short.

[45] It was supplemented by a strategy guide released by Enterbrain on July 5;[46][47] and the Infinite Space Setting Document Collection published by SoftBank Creative on February 1, 2010, containing artwork and developer commentary.

[57] Kat Bailey of 1Up.com noted homages to 1970s Japanese science fiction,[55] while Edge Magazine praised the narrative as "neatly grafted" onto the gameplay systems.

[8] Matthew Kato of Game Informer called the characters cliche and the story "ordinary",[9] while GamesRadar enjoyed the balance of serious drama and humor.

[59] Matthew Castle, writing for Nintendo Gamer, lauded the scale of characters and narrative, praising Yuri as one of the best recent RPG protagonists.

[60] Anthony Capone of PALGN cited the narrative as one of the game's positives,[5] and Pocket Gamer's Will Wilson lauded the character interactions and script quality.

[9] GameTrailers gave praise to the anime stills used for cutscenes, but found the 3D ship models unattractive and faulted the sound design for its poor quality.

[4] Hatfield disliked the gameplay during the first few hours due to a lack of flexibility and generally negative about several mechanical choices,[59] while by contrast Castle lauded its systems despite these unintuitive elements.

[64] Its early sales success was attributed to its broad appeal in themes, and the fact that it was an "orthodox" DS title of a type becoming rare in the modern market.

[24] Inaba half-jokingly blamed Sega for under-producing the game, resulting in the limited stock quickly selling out worldwide, but more seriously attributed its lack of sales to the bulky scenario's niche appeal.