I had to reopen up the game to remind myself of what I like about the game's combat. Right off the bat: No random encounters. Praise Aidios! You can fight as many battles as you like and maybe even gain a preemptive advantage.
As for combat, there's the regular attacks, Arts (magic) and Crafts (specials). There's are also S-Crafts which is the Supers/limit breaks. At face value, this is a very normal set of commands. What this games does well is that combat positioning is crucial in battles going smoothly. Attacks can have knock backs to them and certain Arts/Crafts can affect an area or a line. Poor positioning management can lead to missing the opportunity to hitting cluster(s) of enemies multiple times. It also applies to the enemies attacking you. This becomes important during boss fights or just fights with some stronger enemies. This is one of the few games where I used certain characters taunt skills. Mix the above and I seem to recall having a harrowing boss fight or two where I just got by. I guess you can say that this game combines regular JRPG (e.g., Final Fantasy I-X, XIII) battle elements with some TRPG (e.g., Final Fantasy Tactics, Disgaea) elements.
For the story... there are for sure the typical JRPG tropes but if anything this game takes advantage of it being part of a series of games. The lore/story is solid. See FLD's post above.