This is one of Len's pure action/martial arts movies without any horror elements. There is sort of a supernatural element with the magic flower but that mainly just serves to give the main character an altruistic reason to go on this quest and fight these people.
The movie starts with a family looking for a cure for their sick child. They have tried everything. The only thing left is a magical flower that can cure any illness. However, in order to get it, you have to defeat a series of five martial artists. You might call it a challenge of five gauntlets. The flower is really just a McGuffin. It's a reason for Len to do all of this.
The movie centers around a series of five fights. There are only a few fights so each one is fairly long and involved. He varies up the enemies and style of the fights fairly well to keep it from being too repetitive. The fights themselves are pretty well done which is good since they carry almost the entire movie. Leo Fong only has one fight scene which doesn't impact the main plot but it somehow looks better than most of the fight scenes he had 30 or so years earlier when he was starring in movies. He actually looks like the skilled martial artist he was. I'm not entirely sure that I buy Len as a historian but it doesn't really matter past the setup anyway.
This is a movie for fans of martial arts cheese. It has a McGuffin plot that serves as a loose excuse for why the fights are happening. I really enjoyed the movie but it is what it is.