By, far, the most notable edition to Naruto: Ultimate Ninja 2 is the plethora of new characters. If that sounds like it won’t float your boat, odds are the other minor features aren’t going to be the life preservers. Even though it's no shadow clone, it doesn’t so much improve the original as it builds upon it. You'd have to be a true fan to distinguish it from the last game, but this sequel is still the easy choice if you had to pick between the two.
Keep in mind these games are Americanized versions of what’s long since been available in Japan. It's an assured guarantee that this won’t be the last Naruto your PS2 will see. So if you’re still happily rocking out to the first game, and you’re on a tight budget, we wouldn’t blame you for waiting for the something still more ultimate.