This is really good for a demo. Fun gameplay loop, fantastic art scenes, a strong starting point for the gameplay mechanics
One thing that could provide a nice bit of extra challenge to the gameplay loop would be occasional wandering characters; Managers checking up on Regulars, Regulars returning paperwork to Managers, Managers going to talk to Shareholders, that sort of thing. Wandering characters would give Ghost a reason to stay on his ethereal toes even after corrupting all stationary characters in a level.
Such a mechanic could even be used to affect how Ghost uses stamina e.g. Ghost can choose to possess a wandering character in order to send them away for the day thus removing the threat but losing out on corrupting a stationary character (lower risk, lower reward gameplay) or he can choose to keep corrupting stationary characters and simply keep an eye out on wandering characters (higher risk, higher reward gameplay).
This idea would also allow for all characters to be more recurring if they can occasionally visit different levels as a wandering threat. If taken to its ultimate conclusion, it could also allow lewd scenes between characters on different levels (e.g. Regulars and Managers lewding each other). It also gives the player a reason to continue visiting past levels after corrupting all 4 stationary characters.
Anyway, great demo, really enjoyed it. Good luck on this project.👍