From a Steam review:

This is a game from 2008 originally called Mozart: The Conspirators of Prague/Mozart: The Last Secret. It was only released in France on PC. There is NO mention of this on the store page, but it is the exact same game with barely, if any changes, besides being in English. It has the same outdated gameplay, despite developers insisting in the Steam discussion page it is "revamped."

Thank you!

Lovely game BlackBoxx.
But confused if this is a puzzle or an adventure game.