The battle system's mostly based on Super Mario RPG, but with a greater variety of and more complex action commands. For example, one type of action command that appears throughout the game, mostly in the major boss battles, starts some kind of mini-game in which the player gains full control of Ryou (the protagonist) so that he can move around, jump, and attack.
For the first boss, the battlefield starts collapsing into a pool of lava below and Ryou has to climb up the falling platforms so that he can attack. In the second boss, the enemy starts pressing a Reset button that restores his HP, and Ryou has to get past a conveyor belt flooding with candy so that he can knock the enemy off of the Reset button.
The game also has a total of 18 playable characters, with the party changing constantly throughout the game. With a few exceptions, most of the time once a character leaves you never get to use him again, so customization and the like are kept to a minimum (although it is present to a certain extent).
Another aspect I've added is a selection of special abilities exclusive to the main character based on the Star Points system from Paper Mario.