The rhythm action game received a launch trailer to showcase its screen-tapping soundtrack.
Demons' Score was developed by iNiS, the studio best known for the classic DS rhythm game Elite Beat Agents.
Users can download additional tracks, voices and character costumes for the game through in-app purchases.
Demons' Score is available now in the App Store for £4.99 ($6.99).
An Android version of the title is due to be released at a later date.
Gallery - 'Demon's Score' screenshots:
Copyright: Square Enix