The story of this particular game is explained here:
The Demons page in particular shows of many demons that are potential allies and enemies, and explaining their involvement in the previous game. The Systems page goes more into the gameplay mechanics, such as combat, recruiting demons, and many other features for those curious about what is in SMTIV Apocalypse. Fans of the previous title will be glad to know many things appear to be unchanged from the original, such as equipment changing your appearance, the Smirk system, demon recruiting and fusion, and much more. There is far more, and you check them all out by accessing the website here.
