14 Mind-Blowing Batman: Arkham Series Facts

In the original game when you're hunting down Warden Sharpe, just as you open the doors to the penitentiary you'll hear a chorus of cheers and chanting from the inmates trapped inside.

This is actually Rocksteady's way of getting everyone who worked on the game in the final version, as what you hear is the combined recording of all 40+ members bellowing their lungs out.