Second movie starring Mahershala Ali and Naomie Harris after the Oscar winning movie Moonlight (2016). Both Ali and Harris were nominated for their performances, with Ali winning in the Best Supporting Actor category.
One of two films released in 2021 entitled Swan Song, with the other one starring Udo Kier. The two films' plot lines share nothing in common.
The main cast is all also part of the Marvel Cinematic Universe. Mahershala Ali is Blade in Blade, Awkwafina is Katy in Shang-Chi and the Legend of the Ten Rings (2021) and Glenn Close is Nova Prime in गार्डियन्स ऑफ द गैलेक्सी: ब्रह्मांड के बॉस (2014). Naomie Harris has also portrayed Shriek in वेनम: लेट देयर बी कार्नेज (2021) which is part of the Expanded Marvel Cinematic Universe, run by Sony.
The Echo bar scene on the train where Cameron and Poppy met is based on a similar box of biscuits scene in The Hitchhiker's Guide to the Galaxy.