The World Ends With You is an awesome game, with one of the best and definitely most innovative battle systems.
Square Enix is known for Final Fantasy, Dragon Quest, and Kingdom Hearts, but those genres can be topped easily by Square Enix.
TWEWY, on the other hand, is entirely unique and a fantastic addition to the RPGs that MUST be played.
Why? Because of it's many wonderful features.
Gameplay: The Stride Cross Battle System uses both screens to battle the same set of monsters, uniquely allowing the player to use the touch screen to control the main character and the buttons to completely annihilate the monsters, with your partner in the top screen, your stylus can't seem to beat down with the pins you have.
Graphics: The backgrounds of Shibuya stylized into some very attractive, youthful graffiti art works very well with the themes revolving in the game. They also compliment each of the characters quite well, because the characters all seem to belong, no matter how spunky or plain they look.
Music: Strange techno with Japanese-accented English vocals.
What more can you say? You either love it or it stays in your head until you're hypnotized by it. It works really well with the stylized Shibuya backgrounds, as shown when you enter battle and seem to naturally expect music and monster bashing sound effects to harmonize.
Storyline: Although the game is so heavily influenced by Japan's culture, the translations came out pretty well, and as a result, it has a commendable plot with all the drama that a Western audience can relate to.
All in all, (well, at least all of which I believe makes up TWEWY) The World Ends With You is a huge step forward into INNOVATIVE and ENJOYABLE RPGs for the DS.