Shin Megami Tensei: Synchronicity Prologue is a game developed by Den-fami Nico Game Magazine’s Ladybug team for PC. The game was a limited time free offer on Atlus Japan’s official site from October 16th to December 24th, 2017. An unofficial English patch has been released by Brento_Bento.

Initially, the game was labelled a hoax (嘘です, uso desu)? in the Japanese trailer for Shin Megami Tensei: Strange Journey Redux on October 13, 2017 upon which it received strong positive feedback from viewers for the production of such a game. Three days later it was revealed to be a fully playable game ready for public access as part of the 25th anniversary of the Megami Tensei series and marketing campaign for Shin Megami Tensei: Strange Journey Redux.

Taking place during the events of Shin Megami Tensei: Strange Journey, Jack Frost is synchronized with the mind of a human in order to traverse and fight demon hordes. He rescues the non-synchronized Jack o’ Lantern after he was frozen by Black Frost, who decimated all the Jacks that previously attempted an assault.