A very solid sequel to Aria, using a lot of the same ideas but amplyfying everything to an extreme. The game is huge, and has a lot of hidden mecahnics to chew on, with some souls being useless and some being completely broken. But experimentation is the key, and the game has a lot of ways of testing the player.
I recommend playing with Definitive Edition+ hack mainly because it fixes the behavior of Luck value and adds a bunch of small bugfixes. I finished the game on a real DSi and didn't notice any issues.