Children of Mana has cute graphics and the battle system feels like an improved version of the SNES Mana games, but it lacks depth/substance so if you're looking for an RPG I don't recommend it. It's pure randomly-generated dungeon crawler stuff like Persona 3/4 without any of the social schedule things. I think what it does have is fun, but it feels sort of like... half a game, to me. Very minimal story and characters, pretty much the whole thing is doing generated requests and smashing monsters.
Haven't played any of the other games.