holy crap! I had no idea Ar Tonelico 3 was a thing! does it play like any of the other two?

Yes and no. it returns to the AT1 system of using three vanguards and one reyvateil. But the costume system is gone now replaced with personas. and rather than unlocking new songs you unlock hyumas which you can connect two four different 'burst' beats. to do things such as healing magic mixed in with buffs and status effect skills. Two vanguards are ai controlled while the third is player controlled and you can swap out which one you use at any time. The battle system feels sort of like tales of vesperia in which you have free movement across the screen and can attack and dodge as much as you can combo. but you still have to keep an eye on your reyvateil as if a enemy gets into their magic feild. their burst gauge stops rising and they take damage until removed.

its also 3D now

And I fucking love it

each reyvateil has its own battle music which changes depending on which hyumas you use, and purging is when you attack at the high points of the song, fighting in rhythm to the reyvateill's song and causes her to get 'excited' and remove a layer of clothing so they can absorb more power from the planet to cast stronger magic. you purge 3 times until they are in their underclothes. (with a hearty blush) and to purge a fourth time activates a flipshere. in which they invert their cosmosphere into the real world and basically attack the enemy with impunity doing sexily large amounts of damage.

A fun thing is when you purge. you can either do it in rhythm with the battle music which gives you a nice peice of eyecandy. or just do it on a whim. to purge you hold one of the r or l buttons and shake the controller once like hitting a cymbal on a drumset. and each of the trigger buttons is linked up to one of the hyumas you installed so... yeah I fucking love this game