My action game comparisons mainly come from the mission structure (20-30 minute levels with a boss at the end, or levels that are just a boss) and the combat. Like how each enemy has their own attack patterns, you can dodge or block them on reaction and then punish accordingly. Take Flamelurker for example, he will attacks fairly aggressively and does big damage (well, everyone does big damage), but all of his moves are dodgeable and you can punish him if you strike at the right time. It's more reminiscent of a Ninja Gaiden boss battle if you ask me. Of course it has a pretty thick RPG side as well, with stats, classes, spells, crafting, etc. It feels like a mashup of the two genres to me.
And now I've made Penelo a Red Mage. Seems like a good all-around class since she gets time magic, green magic, white magic, black magic, AND arcane magic...