This is an early showcase for a then young Riki Takeuchi. Looking something like Chow Yun Fat doing an Elvis impersonation, Takeuchi appears to have cult status in Japan, and probably well deserved. Although he has a limited range, he plays that range to the max, and with a great deal of energy.
This is one of a myriad of films produced between 1970 and 2000 that borrows heavily from the Clint Eastwood Westerns directed by Sergio Leone. Here, the references are more subtle than we've seen in other films from any country; but it finally adds a bit of bizarre humor at the end, with Takeuchi whipping out a mini-gun. (Italian westerns were filled with Gatling guns, to increase the body-count. In Leone's Fistful of Dollars, it's in the scene where the Mexican soldiers are ambushed.) The point being, this is a postmodern action film, not intended to be taken all that seriously. The film-makers know we've seen it all before, they just hope we want to see some more of it. And it's all done fairly well - action fans will enjoy it immensely.
Very professionally made little film; and a good introduction to the acting talents of Riki Takeuchi, who would go on to continue developing this type of character in many films.