Sleepless

Max von Sydow requested that the parrot featured in the film be named Marcello. This was a tribute to Marcello Mastroianni, whom von Sydow had befriended while working on various Italian film productions earlier in his career.

When Detective Ulisse Moretti discharges a firearm in the apartment, the acoustic pressure and muzzle flash of the gunshot would likely cause an immediate flight response in the parrot. The bird remains stationary on its perch, which is inconsistent with the typical behavior of a reactive avian species under extreme auditory stress.

The final scene and the closing credits are presented simultaneously, utilizing a split screen or overlay format as the narrative concludes.

The German theatrical and home video release was censored to comply with national distribution standards. To obtain a SPIO/JK rating, the distributor removed 27 seconds of graphic violence. A secondary version, edited to secure an "Not under 16" rating from the FSK, lacked two minutes and 34 seconds of footage. Although the Federal Department for Media Harmful to Young Persons (BPjM) removed the film from its index in 2016, only now in July 2026, the FSK rated the uncut version "Not under 18", putting an end to the film's German censorship issue.