In the "Curtains Down" mission, the player may access the locked door in the upper corridor (the one the worker with the screwdriver is trying to enter) by killing all the rats in the large basement room that has the long sideboard in it. Shortly after the last rat's death, a golden "Rat Casino" key card will appear on the wooden sideboard. This key card will open the otherwise locked door to reveal a small room divided by bars behind which a group of rats are boxing and playing poker.
In the "A dance with the devil" level, the sharks in the HELL club eat any bodies that fall into the tank. The player can keep tossing in bodies and the sharks will get fatter with each one they eat.
In the "You better watch out..." level, there is an unconscious party-goer behind a couch in the grotto area. If pulled out and left exposed to be found by a guard, she will be woken up as usual.,However, she will constantly keep falling unconscious. The guard that wakes her up will eventually get tired of doing so and shoot her to death to dispose of her in a body bag. Despite the player having little to do with this, they can still be blamed for the murder and shot at even when the guard does the killing in plain sight of witnesses.
In the "Curtains Down" mission the player is able to enter a storage room. On a shelf in the corner, lies the mask from Phantom of the opera
Takes place before and after Hitman Contracts.