When reviewing a movie like this, it's hard to know where to start, and where to end, as this movie is so full of crazy gadgets, wacky gimmicks, and over-the-top action. But basically, this movie (based on a 52-episode TV-series from the 1970s) is a fun romp to watch.
The plot is somewhat as follow: When their city is overrun with criminals, the local police-force turn to their local hero, Yutaka Daimon, and his best friend/karate-robot/motorcycle, Zaborgar. But they suddenly find themselves over their heads, when the evil mastermind Dr. Akunomiya attacks the town, extracting the DNA of scientists, top-politicians and other highly influential people, in order to build a giant killer robot, which will give him unlimited power. This evil doctor has a bunch of crazy hit men with him, and also the seductive Miss Borg (who has an on/off relationship with Daimon), all forming the powerful criminal gang called Sigma.
But they didn't figure Daimon and Zaborgar would be able to defeat them, and underestimated their powers, which led to a huge battle for the ultimate fate of the universe midway through the movie. However, the story doesn't end so easily, and many years after the apparent ultimate showdown, Daimon and Zaborgar would have to fight again, which is where the actual movie begins for real.. kinda.
Anyway, I'll give this 7/10, as it's one of the more entertaining entries in the never-ending crazy-cinema wave from Japan, although a bit silly, it never leaves the audience bored, as the imaginative craziness never stops!