Sigma Harmonics is an adventure RPG for the Nintendo DS and was published by Square Enix on August 21, 2008. The game was developed by some of the people behind Dirge of Cerberus: Final Fantasy VII at Square Enix and the company Think Garage. There is a heavy emphasis on music in the combat and the story deals with dark subject matter such as death and battling demonic monsters invading our reality.
The main character is Sigma Kurogami whose family guards a clock sealing off the demon Oma. Just a simple high school student, one day his past is rewritten and chaos enters his present. He must then team up with his friend Neon to solve a slew of new murder cases.
The Nintendo DS is held sideways, like a book. Dialogue is split between both screens and is a key factor in solving the murder cases. You will talk to many characters to unravel clues and then be tasked with arranging the clues on a grid in a logical manner to trigger flashbacks or cutscene sequences.
Battles take place on both screens as well. Character battle animations are shown on the left screen and a selection of three cards is on the right. The cards each have a meter which take time to fill. Once they are full the card can be dragged into a slot at the top of the screen and will be activated with effects shown on the left screen. The song playing has an EQ and this EQ effects how a cards meter will fill. Some songs have a tendency to charge the leftmost card fastest, others are balanced across all three cards while some songs favor the card on the right. The song can be changed while battling so that the player has indirect control of which card charges fastest. The card must also be appropriate for the direction of attack, since it's possible to miss if the card is directed forward but the enemy is to your characters left. It remains to see if they counter intuitive battle control works better in practice than in theory.