The fitness componnent aside, which works very well mind you (gained some muscle, lost some kilograms, working up quit the sweat). The game honestly features so many elements it is scary. A summery:
> enemies have elemental weaknesses
> some enemies have charge attacks
> others are support enemies, offering buffs (attack, defence).
> others offer full heals or even revivals
> there's a potion crafting system that's the perfect balance between open and not too complex
> you can craft buff potions
> buffs from gear set bonusses (yes) stack with potions
> there are potions that change the element of your attack for 3 turns (yes)
> there's a skilltree that rewards unique abilities
> some potions allow doubling or received resources i.e. double XP, double money or double items received for a fight (a grinder's wet dream)
> no obtuse droprates, everything is set in stone
Add to that that some attacks are more powerful, but way more draining for your own body, and you've got an excellent JRPG with some serious strategic combat.
If I'd had to voice complaints its the reused levels and bosses (Kamiya would be proud) and frequent interruptions from message to take a break (probably a health law popping its head).