Set during the events of Shin Megami Tensei's nuclear holocaust, NINE follows demon hunters known as "Debuggers" as they rout demons from a computer network that also overflow into reality. NINE also marks one of the very few instances in the series where player gender is selectable, rather then pre-determined.
The NINE in the games title is meant to denote the number of alignments available in the original series (Law, Chaos, Neutral, and their Light-Neutral-Dark variants). The soundtrack consists of various rearranged tracks from the original Shin Megami Tensei. Though demon designs were once more handled by series veteran Kazuma Kaneko, character design was delegated to Yasuomi Umetsu, who had previously provided illustration work for Castlevania 64 and Contra: Hard Corps.
While NINE was initially developed as an MMORPG, the game was instead released as a single-player action RPG, with an online version TBA at a later date. Though said version was cancelled due to poor sales, the game would serve as a prototype for the later Cave-developed Imagine: Online.
In addition to demons and their levels, their races and race alignments are also listed.