Avalon Code is an action RPG boasting incredible graphics, a deep and engrossing story, and innovative game play mechanics. Using the main character’s 'Book of Prophecy', players can modify the rules of engagement during battle as well as weapon and monster attributes. The player even has control over the story as it changes depending on which gender the player chooses to play as, enhancing the ability to immerse themselves into the story.

This game came out a few weeks back for the DS. It has some pretty decent graphics for ds, and is good, if a little basic.
The central gimmic is the "Book of Prophecy", which is an item you can use to modify pretty much everything. Basically, you whack an item/npc/enemy, and they get recorded into the book. You can then fuck around with their atributes, which are represented by a small 3x3 grid containing blocks. An example is near the start of the game. You fight a troll, but it seems to have a lot of health. You whack it with the book, and find it has a "Stone" block in it, causing its health to be much higher. You can take this out, and replace it with a "Sick" block, and it will be a very easy opponent.

I haven't played much of this, but it seems pretty enjoyable, and the book thing is a pretty enjoyable gameplay aspect.

Played the demo off the Nintendo Channel a while back, cool concept though I couldn't get the hang of the whole Book of Prophecy thing.  I could pull elements/items off but couldn't figure out how to put certain ones back on to affect the enemy in different ways.