A digital app that is a separate application from the main game where you can fully enjoy the world of Echoes of Aincrad, an RPG set in the floating castle of Aincrad.

In addition to content not seen in the main game, such as character and enemy concept art and background art, it includes Unanswered//butterfly, a feature-length promotional animation of approximately 120 minutes depicting a separate story from the main game!

Furthermore, the digital soundtrack includes various songs from Echoes of Aincrad and Unanswered//butterfly. Immerse yourself in the world of Echoes of Aincrad with this app!