The Mystery Man is a mysterious character who seems to have control over the player. He appears only at the end of BOSS FIGHT, when the player has killed The CEO. He has no in-game model, and is instead super-imposed on the player's screen, as though over a radio signal. It is presumed that his actor is a member of the SUPERHOT Team.
(after killing The CEO)
"Yes! You have served me well. Now, dispose of yourself."
(a window above a high drop shatters)
"Just walk from the window."
(the player jumps out of it)
"Stop. You've been a good boy."