There, they discover that the Firmament Project was an effort in the late 19th century established by Andrew Carnegie, Marie Curie, Karl Marx, Nikola Tesla, Konstantin Tsiolkovsky, and Jules Verne to preserve humanity by developing interstellar travel, and the Swan and the Realms are all part of a massive starship called the Atelis, which launched in 1910; the events of the present are about three hundred years since its launch.

The Mentor admits that she had tricked Turner into believing she was on his side, before sedating him and placing him into "the Deep Sleep", a hibernation process used to create Keepers, which erased all of their prior memories.

[8] Softpedia praised the world design, but criticized the limitations of the narrative and of the character interaction with the environment, particularly with ascending stairs that were hard to notice.

They noted that Firmament had a "built-in audience of Myst fans" to whom the quirks of the developer would appeal, but newcomers "might be impressed by this world at first and will then struggle to engage with it".

[10] Inverse criticized the narrative as "too thin" compared to Myst, Riven and Obduction, but praised "Cyan's ability to make players care about fictional worlds", calling it "the most approachable game in the company's history" and a "perfect primer for the puzzle adventure genre at large".

Fans noted that they were not informed of this potentially controversial change during the Kickstarter campaign, believing that it resulted in an inferior game and amounted to plagiarism of actual artists.

[11] In response, Cyan released a statement on June 9, 2023, which goes into detail of their use of the technology, noting that it was used to alter existing voice acting and was used to "ideate" the writing and art, but not used to provide assets directly.