Donnie Yen sustained a heavy injury in his right shoulder while shooting the fight scene in the gym with Dick Wei. The accident can be seen in the shot where he gets kicked in the face, leaps outside the ring onto the wall hitting the shoulder and falling on the floor. The injury still affects Yen to this day.
Co-star Kenny Perez revealed in a recent interview (ca 2009 or 2010) that the production got interrupted by a triad gang that demanded protection money from the film crew while shooting occurred at a certain location that the gang happened to control. When the demands went frequently, Donnie Yen and Yuen Woo-Ping got fed up by the threats and decided to fight them off whenever they showed up, with Perez willingly joining in to help them. Perez described the whole experience as "crazy but highly fun".
Shot shortly after his debut movie Siu Tai Gik (1984), this was Donnie Yen's second movie out of a three-picture deal with Yuen Woo-Ping's production company. However the aforementioned movies didn't do well at the local box-office convincing Yen to off the deal and take a break. Yen returned to the States and worked at the Chinese Wushu Research Institute for a year before returning to Hong Kong to give a shot at acting again by taking up acting lessons at TVB and signing with D&B Films Company.