According to the German Amazon page for Mata Hari it seems like the game is being released on the 21st. this month. The official site has also been updated with info about the seductive gameplay mode which you'll use to whore yourself out to the richer gentlemen (and women) of the Belle Époque.
Over on the English Amazon page for A Vampyre Story, its release date is also set for the 21st. contrary to what we reported earlier. Who is right?
Rhythm based mini games though? I can't say that sounds like my cup of tea. Hopefully it'll mostly be a cool extra for those that enjoy it rather than something the player needs to do.