The creativity and mechanics shows an interesting break from more traditional strategy games like Disgea or FF Tactics.
Music: Tenpei Sato's soundtrack for this game is one of the best I''ve heard in the genre. A lot of soaring angelic vocals and fast violins add to the feeling of the game, and provide more quality as standalone music tracks than more primarily atmospheric tracks like those in Disgea. The game actually came packaged with the soundtrack CD as well.
Difficulty: This game can be quite hard. I'd venture to say it is harder than Disgea. The optional dungeons are harder and longer, and there are some story battles that are downright devilish.
Story: It has more of of a "cute" than "funny" bent than Disgea did, but unless you're jaded it should be pretty charming to play through.
Length/Content depth: It's easily a 45 hour game in the story alone, and there is room for leveling up and getting cool weapons and such afterward if you so desire. However it did feel to me to be less in-depth than Disgea. For one there's no new game +, which adds a bit of futility to post-completion activities.
Graphics: In a game like this, the graphics aren't all that important, and they are SD in battle, as they were in Disgea. However the background stills in the cutscenes are quite good in my opinion, and combined with the actual interacting character sprites, it makes the cut scenes more believe-able than Disgea's.
All in all I think this is a must-play for any strategy RPG fan, especially any Disgea fan like myself. The story is engaging and the voice acting and characters are all charming. It's a bit rare but those loyal to the genre owe this one a play if only for its twists to generic game-play tactics.