Mystery House Remake

Wander through an old house with a wide number of rooms. Once you entered the house, its main door will be closed and locked by someone. You need to escape living. While exploring the rooms, find the citizens one by one - dead. it is your task now to find the killer before he (or she?) ends up by killing you. This is a Macintosh remake of a game for the Apple II started back in 2003, offered as freeware since then.