The story begins with the game protagonist having dreams about the world coming to an end. And he is the chosen one, although not to save the world but to wield a magic book called the Book of Prophecy. To record everything in the world that is worth recording.
You start the game by choosing either a male or a female character.
To record a targets code, which is a simplified DNA, you hit it with the book. Fortunately no one gets hurt because they can't even see the book coming down on them. With the code in the book, you see different puzzle pieces laid out on a grid, which you are able to remove.
Which gives you the possibility to smash the book on a wounded person and get the targets code. And then remove the wounded code and put it on your enemy by smashing them and putting it into their code, which will cause a debuff such as reduced health. Or perhaps use the book on a poisonous plant, take the poison code and use it on your sword, which then gives your sword poisonous attributes. The game offers you the possibility to manipulate virtually everything.
Fighting is done in realtime on the top screen. You have two weapons and each is controlled with the X and Y buttons. If you get behind an enemy and press A you enter in to a little mini-game where you juggle the enemy up, being able to hit the enemy all the way into space.
You scan something with the Book of Prophecy by pressing B.