The game is quite different from most other RPGs, because it lets you play as both the "good" hero and the villain. The game is divided into chapters, and each chapter is played by either Falco or Rukyu. You switch the two heroes chapter-after-chapter, and lead them to their ultimate battle from two opposite sides. The entire game, including the battles, is viewed from an isometric perspective. The battles are random and turn-based, and the battle field is divided into squares you can position and move your characters on. Both Falco and Rukyu can have party members join them, and both attack mostly with magic. Rukyu uses a special energy called "Soul Power", while Falco cast one-time spells from scrolls he receives after battles.

Dark Half Intro:

Light turns back into darkness and darkness produces light.
Everything begins and ends.

When Heaven and the earth split, and life appeared on Earth, Rukyu already existed.

Rukyu dominated darkness and came to be called Satan.

Satan's power was eternal and the human world feared him.

But then there appears one who would change that fate.

The hero Roda, and 6 paladins fought with the devil and finally, they confined him.
The era in which humans lived in fear became a thing of the past