Battle system trailerAnd since I went and posted this on Gematsu I might as well put it here too. I translated the info in that trailer:
0:24
When the battle starts choose one kind of song magic to start with. There are cases in which you can't use a song again for a while after using it once. The kinds of songs vary in terms of their "effect" and "power".
0:40
Battle Skills
Attack by pressing the (triangle)(circle)(square)(x) buttons
You can only use each attack the number of times indicated
The (circle) button powers up the (triangle)(square)(x) attacks
0:53
Press the (circle) button in time with the enemy attacks to defend
The number of times you are able to guard is limited just like your attacks
1:03
Heroine's endurance level
There is a 4 level barrier that decreases every time they receive an attack.
If all of the barriers are destroyed then it's game over.
1:13
Harmonics
Actions during combat increase the gauge.
You can use powerful skills that consume the gauge.
1:24
Harmonics
When the gauge has gone up a certain amount the level increases,
and there are various benefits.
1:40
Enemy break
When enemies are attacked their break gauge increases
When it reaches its maximum the enemy is unable to act
1:51
Enemy break
When all enemies with a "!" symbol are defeated or broken there is a "break bonus" and the player gets another action turn.
2:05
Wave Window
This indicates all of the enemies that exist in the field.
The red part indicates the range of effect of song magic.
If all waves are defeated there are no more encounters.
Wave
The right-most part indicates the enemies on the screen.
When they are defeated the next enemies are waiting to appear.
2:27
Burst Level
"Song magic" charge quantity.
The higher it is the more enemy waves you can annihilate.
2:40
Burst Level
The burst level is increased in response to the actions of the protagonist during combat.
2:57
Support by Heroines
As the harmonics level increases the heroines will back you up via "song magic".
3:07
Support by Heroines
The type of support attack will differ according to the kind of "song magic".
3:19
Friend Skills
Comrades in the game whose trust you've earned can also support you.