This was produced on a deceptively low budget. Prodicer Michael Deeley on his memoirs says that it cost between £150,000 and £200,000.
The British paratroopers in the film use sharp-ended metal tent pegs to silently kill their German opponents in the film.
David Hemmings plays a paratrooper in the British Army during World War 2 in this movie, whereas his son, Nolan Hemmings plays Sgt Grant, a paratrooper in the Easy Company, 506th PIR, 101st Airborne Division, US Army during World War 2 in the acclaimed miniseries Band of Brothers.