To simulate bullet hits on walls, grass, etc., instead of using squibs, spots were marked for snipers to shoot on, even when actors were near. This method (which is common practice in Thailand, where this movie was shot) was used, because the setting up of squibs were thought to be too time consuming. Actor Eddy Ko still has a scar on his chest because one bullet ricocheted and hit him there.
After the film's completion, it was shelved. Woo commented that the film was all over the place in tone with sometimes being very emotional, something being as violent as a horror film and that it did not contain any popular actors. As of 2004, Woo stated he had not seen the film in it's finished form.
Even though he disavowed it at first (mostly due to Golden Harvest's re-editing), John Woo calls this his first "real" film. He also enjoyed his first international shooting experience; Woo thought the Thai crew was very professional and willing to partake of dangerous stunts even the noted Hong Kong stuntmen would not tackle.
The movie was filmed in 1984 and 1985 and then shelved. After John Woo's amazing box office success with Ying hung boon sik (1986), it was finally released.
The drug/sex scene was imposed on John Woo by the studio to give the movie more "production value" for sale to foreign territories. Most non-Hong Kong versions run about 82 to 84 minutes, with most of the major cuts coming not in the violence, but expository scenes such as those between Chung and his sister-in-law.