This isn't the first time Prime Video carried Kamen Rider in their service as they are currently streaming Kamen Rider Black Sun and previously had Kamen Rider Amazons available in said service worldwide.
A reimagining of Shotaro Ishinomori's classic Kamen Rider series, the film was written and directed by Neon Genesis Evangelion creator Hideaki Anno. The film premiered last March 18th, and is currently the highest earning film in the Kamen Rider franchise.