Ar tonelico: Melody of Elemia is a role-playing video game developed by Gust Corporation for the PlayStation 2 and originally published by Banpresto in 2006.
Ar tonelico features a turn-based battle system akin to those of the Atelier Iris series. The active party consists of up to three fighters in the front and one Reyvateil in the back. An action can be chosen for each fighter as their turn arrives. An action bar at the top of the screen indicates the turn order for every character and opponent involved in the battle. Fighters may choose to strike the enemy, defend themselves, use a skill, use an item, or to protect the Reyvateil.
As long as any fighters remain alive, the Reyvateil can not be attacked directly by the enemy, and can only be targeted by charged attacks. When targeted, a number of circles are shown around her to indicate the number of fighters that must protect her (instead of attacking) before the enemy's next turn to completely block the attack. A successful defense grants the fighters an option to mount a devastating counter-attack at the cost of one harmocrystal.Harmocrystals are activated when the Reyvateil and the rest of the party work well together, a measure of which is represented by the Harmonics bar at the bottom of the screen. Harmonics improve with each successful attack from the fighters, defense of the Reyvateil, and gradually over time, but decreases whenever an enemy lands a successful attack. When the bar fills, the party's attacks become stronger and one harmocrystal is activated. The number of active Harmocrystals affects the number of counter-attacks the party can mount, the skills available to each fighter, as well as the types of items received at the end of a battle. A higher level of Harmonics also allows the Reyvateil to sing faster.
Unlike fighter characters, the Reyvateil does not need to wait for her turn and can be given commands at any time during the battle. Instead of attacking directly, she supports the party by using Song Magic. Her MP will decrease as long as she is singing, and stopping the Song will cause her MP to recover over time. Red Magic can be charged for any length of time before being released onto the enemy as an attack, whereas Blue Magic immediately takes effect and continues to remain in effect as long as the singing continues. Both kinds of magic become progressively stronger as the Reyvateil continues to sing the same Song, and power up faster with each incremental level of Harmonics. Stopping or changing the Song will cause the next spell to begin powering up from its basic level. The Reyvateils practice magic by “singing it". Hymns and Song Magic are powerful, they can be used for killing and healing. Therefore, unlike many other games, the songs form an integral part of the gameplay and story.
Gameplay
https://en.wikipedia.org/wiki/Ar_tonelico:_Melody_of_Elemia
