The Battle System is easy to get a good grasp on - it has a class system like Final Fantasy V that controls what abilities the character has and affects their stats (e.g. a Black Mage is far weaker physically than a Monk but has stronger magic). But you can also equip a second set of abilities from a different class - so you could equip a Black Mage who would have a high Magic stat with White Magic. Then it also has the Brave and Default actions - Brave lets you take turns early while Default allows you to save up turns so that you can use Brave then still be able to take action the next turn.
It allows you to create clever strategies and if you cleverly plan out moves based on your character's speeds, you'll be able to revive team members and have a team mostly at full health in a few turns.
The only flaw I really saw with it was that some of the abilities on bosses were somewhat unfair. The max damage you can cause per turn is 9999 unless you use a special ability - but the Dark Knight of the game has a move called Minus Strike which does damage equal to the amount of HP they have lost. So he can insta-kill your characters with a move that you can't use to do more than 9999 damage.
Graphically, the cutscenes at the beginning are amazingly beautiful but the rest of the game is done in a kind of chibi style - like Final Fantasy III when it was upgraded for the 3DS. There is only one single cutscene after that which is at the very end of the game - the rest of the game is done in that chibi style which isn't bad, but it makes the main characters seem a lot shorter than literally every other character you talk to.
Story is where the game excels - it starts with a simple 'awaken the four crystals to save the world' and is very focused on what characters say - but things then become a lot more complex. I will admit that the second half of the game is somewhat tedious, especially if you do all the sidequests, but it is to add to the fact that the journey takes a long time. You get the true ending if you keep playing through but there is a second ending that you can find after you have started chapter five, finding it doesn't really do anything except show you would happen if you took that action instead of continuing onwards endlessly.
Anyone who liked Final Fantasy, especially the early ones, would love this game.