I do not pretend to be any kind of Chinese scholar, but I've seen dozens and dozens of Kung Fu movies and this is certainly one of the strangest. Although it was a bit hard for me to follow, it seems the "baby" of the title, Red Boy, (who is more like 12 or 13) is the antagonist here, who kidnaps a ruler. The Monkey King and "Pigsie" (that was actually the name given in the subtitles) a comic relief character with pig's nose and ears, try to get the ruler back.
Besides the basic Kung Fu action, this whole affair seems heavily influenced by traditional Chinese opera. Some of the interactions seem overly slow and over-choreographed, and now and again had a kind of Busby Berkeley vibe to them. People kept popping between Heaven and earth to fight, and I never did figure out why.
Weapons and people appear and disappear. Trees and statues come to life and then turn into people and fight. There's a Kung Fu centaur and flame-throwing chariots. Throw in some sci-fi theremin mixed with Chinese gongs and you get the idea. I'm not sure how accurate the subtitles were here (I caught this on El Rey), but I found it all pretty hard to follow. This movie was in Mandarin and I can never understand any inflection or tone that helps me understand things in Mandarin or Cantonese like I can in other languages. But it's basically all action, and at just over an hour I certainly can't say it was boring, just a bit confusing.