Mysteriet på Greveholm ( "The mystery at castle 'Count's little island'" )
From Wikipedia (about the tv series):
The plot follows a family deciding to spend their Christmas on the country. They intend to rent a small house, but stumble across an old castle. Mistaking two thieves for the owners they "rent" the abandoned castle. Soon the children of the family, Ivar and Lillan, discover that the castle is haunted. At first the ghosts seem to be evil, but soon the children (who are intrigued instead of terrified) befriend them. But there is something else in the castle, an evil even the ghosts are frightened of.
Mysteriet på Greveholm is based on the really good and successful television Advent calendar with the same name (broadcast on SVT, Sweden's state television, in December 1996). The TV series has several times been elected the best televised Advent calendar ever.
There were two more computer games released although none of them were Mac compatible as far as I can remember.
Comes on a Hybrid disk:
Mac OS 7
16 MiB RAM
30 MB hard disk space
Min 75MHz Pentium
Min 16MB RAM
Hybrid Mac/PC .iso image, compressed with Stuffit 5.5
The disk image contains installers for the game in the following languages: English, French, German, Dutch, Italian, Spanish, Danish, Norwegian, Finnish, Swedish