What we paid attention to when thinking about the movements and motions for the ghosts is the fact that they're ghosts.
They're dead, but not corpses. While we were conscious of the inorganic, emotionless fear of death, we used the organicness and emotiveness of humans to express fear.
As a result, as well as the slow movements of a corpse they also have emotions, a purpose and a personality, and specifying their movements so that a heightening of that emotion translates into attacks.
When this was actually being incorporated into the game we needed more variation and interestingness in the enemies, so worked hard to balance that.
I hope that during the game you listen to their words and use them to understand their dying wishes.
Tsuyoshi Iuchi (planner)