Allegedly filmed in between Jackie Chan's two Seasonal Productions movies, Snake in the Eagle's Shadow (1978) and Drunken Master (1978), but not released until after the success of the latter Seasonal Production due to Lo Wei's financial constraints. This movie was filmed as a Mandarin-language movie, yet the focus on the dubbing switched to Cantonese, due to the success of the Cantonese-language Seasonal movies, and other studios (i.e. Golden Harvest) beginning to lean into Cantonese as well. This is why most releases feature Cantonese as the only Chinese dialect option, despite the fact that the harder-to-find Mandarin track syncs up with most of the actors (save for the South Korean cast members) far more accurately.
Like many other Hong Kong kung fu movies, this movie was scored with various musical cues from U.S movies, mainly Jerry Goldsmith's score for La canonnière du Yang-Tsé (1966).