Fantasian began development in 2018 after its producer and writer Hironobu Sakaguchi replayed Final Fantasy VI and was reinvigorated to create an emotional role-playing narrative.

Sakaguchi agreed to work with Square Enix on Neo Dimension at the invitation of producer Naoki Yoshida, whose Creative Studio 3 co-developed the port with Mistwalker.

Neo Dimension saw positive reviews from critics; praise continued to be given to its presentation and gameplay, opinions varied on its story and difficulty, while the Switch port was noted for technical issues.

Fantasian is a role-playing video game in which players take on the role of protagonist Leo and a growing party as they explore multiple locations across several worlds including the land of Vibra.

[26] The denser structure of the second part, with new gameplay elements and an expanded skill system, was attributed to a strong commitment to providing a polished experience inspired by the need to work remotely.

[27] For the Memory sections, Sakaguchi used a similar approach of combining text with illustrations and sound as "A Thousand Years of Dreams", a series of short stories within Lost Odyssey (2007).

Sakaguchi described Goto's designs as doing a good job expression the multiple worlds featured, noting that each lead was given a key color and tied into the story themes.

[15] During pre-production, concept dioramas were created by Walnuts Claywork Studio's Tomohiro Yatsubo, who had worked on similar environments for Terra Wars.

[30] The music for Fantasian was composed by Nobuo Uematsu, who had worked on the Final Fantasy series and a number of Sakaguchi's projects at Mistwalker.

[31] Wanting to break free of conventional music found in the JRPG genre, Uematsu experimented with elements like dissonance and ethnic instruments.

For the final boss, Uematsu decided to write it like a "four-part opera", making Sakaguchi fear they would need to add an extra phase to accommodate the music.

[32] Uematsu felt that Fantasian contained some of his personal favourite melodies, while Sakaguchi admitted to crying upon hearing some of the finished tracks.

[34] A physical CD album, Nobuo Uematsu × Hironobu Sakaguchi Works - Music from Fantasian, was released by Dog Ear Records on July 28, 2021.

[12] The localization was handled by a five-person team spread across Japan and North America including Jessica Chavez, who worked on The Legend of Heroes: Trails in the Sky.

[47] Neo Dimension includes enhanced graphics, an easier difficulty option, gameplay balances, and voice acting in English and Japanese.

[48] While Sakaguchi had previously left Square Enix on poor terms, and had wanted to make a name for himself away from its properties, the situation had softened and he had become a fan and regular player of Final Fantasy XIV.

[47] Yoshida successfully persuaded Square Enix's upper management to greenlight the collaboration, a process Sakaguchi remembered took a long time.

While major story sequences and important conversations were voiced, smaller exchanges were left silent to conserve the game's pacing.

[54] Jeuxvideo.com lauded the Dimengon feature as one of the most innovative RPG elements in recent memory, but faulted some parts as slow paced and a lack of language options beyond English and Japanese.

[52] Caitlin Argyros of RPGFan gave strong praise to the story, combat and soundtrack, though while lauding the environments found the graphics occationally blurry.

[5] RPGamer's James McFaddon positively compared Fantasian to earlier Final Fantasy games, lauding its presentation and addictive gameplay mechanics.

[2][5] Reviewing the second part, Jeuxvideo.com praised the expanded gameplay mechanics and non-linear progression despite repetitive side quests, calling the completed game an essential title for Apple Arcade players.

[6] Argyros was less enthusiastic than other reviewers, enjoying the gameplay expansions but finding the non-linear progression and heightened difficulty detrimental to the story.

[1][6][51][55] Reviewing the full release, James Galizio of RPG Site praised the gameplay and art design, and found the story engaging despite the disconnect caused by the difficulty, with his main complaint being recurring technical issues such as freezes and crashes.

[1] Touch Arcade's gave much of his praise to the art design and game mechanics, but felt the story and later difficulty spikes undermined what was otherwise an enjoyable experience.

[67] Steven Mills of Destructoid lauded the game's presentation, narrative and gameplay, with his only notable complaint being elements of its UI showing its origins as a mobile title.

[61] Kerry Brunskill of PC Gamer enjoyed the narrative and world design, but felt the gameplay became overly hard and complicated during the second part of the campaign.

[65] Ed Nightingale of Eurogamer noted late-game difficulty spikes and found the narrative too conventional, but praised the game as a strong return for Sakaguchi and appreciated having it an accessible form.

[62] Japanese gaming magazine Famitsu praised the gameplay elements and diorama environments, but there were complaints about its traditional structure and longer story segments.

[66] Nintendo Life's Alana Hagues noted hangover issues with its story and difficulty progression due to the original version's two part structure, but praised the overall gameplay design and presentation.