This film has historical importance: it was the first superhero film that was made in China, the first film promotion in Hong Kong that used a hot air balloon, and the first Shaw Brothers production that used a storyboard.
The Japanese tokusatsu TV series Ultraman: A Special Effects Fantasy Series (1966) and Kamen Rider (1971) (both of which were extremely successful in Hong Kong at the time) were the bases for this film.
The English dubbed version of the film accidentally created a plot hole in it by saying that Infra-Man was powered by the Sun, yet when Princess Dragon Mom sends clouds to blot out the Sun, he does not lose his power. In the original Chinese version of the film's dialogue, it's made clear that only his Solar Ray Weapon is powered by the Sun, and it does stop working when the clouds blot out the Sun.
In the original Chinese version of the film, Princess Dragon Mom's name is Demon Princess Elzebub. This is a play on Beelzebub, a name meaning "Lord of the Flies" and attributed to both a Biblical idol and the devil.
In the original Chinese version of the film, the monsters were named as follows: Demon Princess Elzebub, Witch Eye, Fire Dragon, Spider Monster, Plant Monster, Drill Arm, Long-Haired Monster, and Iron Armor Monsters. In the English dubbed version, they were renamed as follows: Princess Dragon Mom, She Demon, Emperor of Doom, Giant Beetle Monster, Octopus Mutant, Driller Beast, Laser Horn Monster, and Iron Fist Robots. The English dubbing also lists Elzebub's dragon form as Flying Dragon Lizard.