Here is an overview of the game, via Rayark:
DEEMO: Reborn is a rhythm game which integrates puzzle-solving elements, a reboot inheriting the heart-warming story of its source material. By bringing DEEMO to 3D, players can fully immerse themselves in its universe. The mobile version, which follows a 2019 PlayStation 4 release and a 2020 PC release on Steam, will be sold for $2.99.
DEEMO: Reborn features over 60 songs, which players can perform in rhythm mode. It’s also chock full of mind-bending puzzles and an ancient castle that’s just begging to be explored. By solving puzzles and exploring the castle’s hidden depths, players can find lost sheet music, and play it to grow the courtyard’s mystical tree. As DEEMO progresses, new locations and storylines will open, uncovering layers of mystery.