Mortville Manor is an adventure game which takes place in 1951. Someone is murdered in an impressive manor, and it's up to Jerome Lange to solve the case. But beware: something otherworldly is going on here...

The gameplay focuses on conducting a detective investigation rather than on inventory-based puzzles, though items must be found and examined for its purposes. Conversations with suspects offer a wide variety of topics. The player wanders through the mansion at his own pace, but events would sometimes occur regardless of his actions. The game's interface consists of a drop-down menu with about two dozen different verbs used for interaction.