The game consists of 14 levels (15 in the UK Steam version of the game.) In all but a few levels, the primary goal of the game is to scare away all the mortals (humans) and cause them to flee the area in fear or succumb to madness.
Ghost Master plays similarly to a real-time strategy game. The player first chooses the ghosts he wants to field in the level. The player cannot field every ghost in every place. Each ghost has one or two types of objects (or "fetters") it can be bound to. For example, a ghost who died during a robbery could only be bound to a "Murder Fetter," whereas a water spirit can only be bound to a bath, sink, or a simple puddle of water.