Tim Curry has cited this as one of his favorite movies of his own.

One ending includes a reference to Perry Mason. While the TV series (Perry Mason (1957)) did not start until after the setting of the movie; the radio series, books, and movies featuring Warren William existed and were quite popular.

The end credits begin with "Clue" game cards that are flipped over to reveal pictures of the main characters and the names of the actors that played them.

There was a fourth ending shot, but subsequently dropped from the film due to the fact that director Lynn did not like or approve of it. Shots of this ending are included in the movie storybook. It had Wadsworth as the solo killer of the bunch, explaining that he killed everyone out of the need for perfection in the world, that all of life's consistencies were not good enough, and further tells the six 'victims' that he has poisoned the champagne he served and unless they find an antidote in three hours, they'll die. Police show up soon enough and trap Wadsworth, but not for long. He gets away from the chief and leaves, locking all the people in the mansion. But as he steals a police car, he notices a 'smell' (the dog dropping smell from the beginning of the film) and realizes the Doberman from earlier is now in the police car, and it lunges for him. The police car crashes, and Wadsworth is dead. This implies that the others got out okay now that the windows were not guarded by the Doberman any longer.

Featured in At the Movies: Enemy Mine/The Color Purple/Out of Africa/Spies Like Us (1985)