We've spent time with the finished game and here's what we think.
http://www.nintendoworldreport.com/hands-on-preview/38481/theatrhythm-final-fantasy-curtain-call-first-look
After spending a lot of time with the final version of Theatrhythm Final Fantasy: Curtain Call, the word that comes to mind often is masterful. The developers took the wonders of the original game and made it even better. In raw numbers, Curtain Call is just bigger. It has more than 200 songs, including all of the songs from the original. It features 60 characters, roughly double the amount in the original. It's also bigger in its modes, with a more in-depth multiplayer mode. The two-player Versus Mode can be playable online, locally, or against the computer. It's an awesome rhythmic battle mode where you and your opponent play the same song trying to beat each other's score while using random special attacks to thwart the other.

The best part is the Quest Medley mode, which replaces the Chaos Shrine from the original. Chaos Shrine had some weird restrictions, where only certain songs were playable in it. That's not the case in Quest Medley. Instead, every song is in play (save Event Music Stages, which aren't much more than a bonus anyway) as you journey through a world map with branching paths, shortcuts, and some honest-to-god RPG adventuring mechanics. Your HP carries throughout the entire quest, so you'll have to use Potions and Tents to heal up as you journey, much like you would in an actual RPG. Quest Medley is an excellent way of bringing this rhythm gameplay even closer to its RPG origins.
I really love the time I've spent with Curtain Call so far. It's fantastic and splendid. Also, I get to make a team entirely of Final Fantasy VI characters, so when it comes out next week, I'm ready to take all you on with my team of Terra, Locke, Celes, and Edgar. And if you're still on the fence, go check out the demo on the eShop. It'll even let you try the new and awesome button controls.