You are Jérôme Lange, a famous private investigator and have been invited to stay at Mortville Manor, only to find yourself in the middle of strange events.
Notes
Maupiti Island, a point'n'click sequel, was released in 1990 for the Amiga and PC.
It seems to be a sort of text and point & click adventure hybrid.
Also available in French and German. There is a website about the game here.
This game was published in France by Lankhor (like Maupiti Island) under the name "Manoir de Mortevielle".
See https://lankhor.net/jeux.php?jeu=15&menu=presentation
According to that page it was published in German too, so we'll need to create two additional entries for those alternate language versions.