This is director Kenji Fukasaku's contribution to the 47 Ronin story, and it represents something of a combination of Mizoguchi's 1941 version and the 1962 version from director Inagaki. Supposedly, Fukasaku wanted to turn the much loved story on its head, but star Kinnosuke Yorozuya used his then extremely high influence with the studio to keep the traditional telling. Fukasaku did get his way with the fight scene, which was choreographed and led by Sonny Chiba, so viewers can expect lotsa action.
Lord Asano is not as well fleshed out as he is in Inagaki's effort, so you learn more about the depth of the insult and its significance from the remarks of his loyal samurai. Kira's greedy and conniving personality, so wonderfully conveyed in Inagaki's film, are also less emphasized. Strong supporting performances are delivered by Hiroki Matsukata (the stuttering Shogun Iemitsu in "Shogun's Samurai",) the ubiquitous Tetsuro Tamba and one of my personal favorites, Mikio Narita (the chess player in "Zatoichi and the Chess Expert".) Mifune has a small, but critical role, as well.
The movie is a visual treat for fans of jidai-geki (period films,) and maintains a better pace than the 90 minute longer film from 1941. But I recommend seeing Inagaki's "Chushingura," first, if you are not familiar with the remarkable 47 Ronin. Then pick up "The Fall of Ako Castle" for the fight scenes.