It is a remake of the OP theme for the original Mazinger Z TV anime series aired in 1972-1974, also sung by Mizuki, when he was 24.
The official website for the upcoming new anime film Mazinger Z/Infinity has released a 60-second music video for its theme song “Mazinger Z/INFINITY Version” featuring singer Ichiro Mizuki in a recording booth and many robot action scenes from the film.
Mazinger Z/Infinity, set 10 years after the final episode of the original TV series, will open in Japan on January 13, 2018.