Final Fantasy I II Dawn of Souls was actually released before the Finest Fantasy for Advance was announced. Returning to the roots of the series, Square gave it's first title a bit more of a remake than in the Playstation version. Graphically, they are virtually identical, with the GBA version being a bit more brightly colored.
The big addition was the bonus area. In Final fantasy II Advance, this is called the Soul of Rebirth. After you complete the game, and the credits roll, you can create a save with a game clear. When you load this game, a new option in the start menu will appear. Access Soul of Rebirth, and your new journey will begin.
Unlike Final Fantasy Advance, you will be playing with characters, that have passed on in the game. Even a character you did not have control of will become available to use.
With this being the second release in the US, Final fantasy II is still a good game to play. The additional dungeon provides good challenge, for those looking to up the playability. This is a great challenge for anyone who is looking for one.