Like Japan's Sentai Ranger shows, Kamen (Masked) Rider has been living on in seemingly endless iterations since 1971. This film is supposed to be a retelling of the first series, or at least the origins of the characters who inhabited that show. The evil shadow-army Shocker, and the two rogue cyborgs they created who turn against them and become heroes and protectors of Japan. Like many modern retellings, both Western and Eastern, the designs are beautiful, especially the subtle and respectful updating of the Rider costumes, and even the monsters they fight, which were also classic combatants from the original show. Also respectful was the lack of CGI effects, which are appearing in increasing amounts in the more recent Rider TV shows like "Kamen Rider Kiva". In the early years, Kamen Rider was mostly a martial arts cyborg hero with a super-motorcycle and, to its credit, this movie honors the simple fun in that.
What didn't work for me was the bland cast of pretty boys and girls (actually the boys are prettier) who seem to be pantomiming anime rather than acting as real humans. The original lead actor from the 70's, Hiroshi Fujioka, was certainly not naturalistic in his approach to the role of Takeshi Hongo either, but his dynamic presence was like watching a caged wild fire on screen. He was also very much an adult, as was his popular replacement, the always charismatic Hiroshi Miyauchi in the next series, Kamen Rider V3 from 1973. Speaking of Miyauchi, he has a tiny token cameo in this but it's so out of touch with the rest of the film that it just feels tacked on.
The point is that, the once exciting, flesh and blood leads who helped create characters we cared about have been replaced with an even younger crowd of sullen hipsters, so skinny that they barely fill out their Rider costumes! Again, I think this is more of an anime influence. However, style alone isn't enough because, like so many re-makes, this one lacks the true heart and soul of the original. It's a little darker and pushes a few tragic love plots but, essentially, it's a very old story which has already been retold in most of the Kamen Rider series (as well as countless other Japanese super hero stories, both live action and anime). In order for this material to still have a life it needs to breathe with real actors and dialogue that matters. Otherwise, lets just watch the old shows because they were already so fun and great!