Ignotus Afterburn 2 was an April Fools' joke pulled by lowiro on those who had accessed the game files within the few days prior to April Fools' Day 2019.
This joke began upon the release of version 2.0.0 (March 21st, 2019), which included a folder titled "ignotusafterburn2". The files contained were a song jacket and a Future difficulty chart file, but there was no audio file. Instead of containing chart information, the chart file contained a message.
AudioOffset:0 - You really thought it'd be this easy?
This led to much speculation that Ignotus Afterburn 2 would be the song for the April Fools' Day event, which most were certain would happen.
Upon the release of version 2.0.2 (April 1st, 2019), instead of Ignotus Afterburn 2, Red and Blue and Green was released (along with a reprise of Ignotus Afterburn). The data files for Ignotus Afterburn 2 still existed, but with the following changes:
AudioOffset:616 - Happy April Fools' from the Arcaea Team.
- The full title of Ignotus Afterburn 2 would have been "Ignotus †Re:Afterburn 2," according to the jacket.
- The number 616 in the altered chart file is a Japanese/Mandarin Chinese homophone (goroawase) of lowiro.