History Trivia / TouhouGouyokuIbunSunkenFossilWorld

* {{Canon}}: All routes are canon in this game with the exception of Marisa's. The events in each other route line up and do not contradict, while Marisa's is inconsistent. Yuuma mentions only a single human to Kanako, not two, and both Marisa and Reimu's scenarios start with them fighting to decide who will resolve the incident, with Murasa's scenario later having her encounter a defeated Marisa on her way home. [With the flooding timeline making this clearly after Marisa and Reimu fought. Meanwhile Marisa fights Kutaka in her scenario; post-flooding and thus post-Murasa, making Marisa's involvement impossible]

* IKnewIt: When the game was first announced, many fans theorized that the "Toutetsu" mentioned by Saki in ''VideoGame/TouhouKikeijuuWilyBeastAndWeakestCreature'' would be the BigBad of this game. Come the full release, the theory turned out to be correct.

* IKnewIt: When the game was first announced, many fans theorized that the "Toutetsu" mentioned by Saki in ''VideoGame/WilyBeastAndWeakestCreature'' would be the BigBad of this game. Come the full release, the theory turned out to be correct.
* OutOfOrder: ''VideoGame/TouhouKouryuudouUnconnectedMarketeers'' managed to come out before the full version of this game, despite it canonically taking place afterwards. Fans theorize that the game was delayed either due to the COVID-19 pandemic, Twilight Frontier focusing more on the console ports of ''VideoGame/TouhouHyouibanaAntinomyOfCommonFlowers'', or a combination of the two.

* DevelopmentHell: The title had been saddled with many, many delays, in due to a combination of the COVID-19 pandemic, the small development team, and the consistent health problems of one of their developers. The game was announced in 2019, and took until October 2021 to be fully released.