This series is the origin of Casshan Robot Hunter and Casshern Sins (and that awful live-action movie was filmed several years ago and Casshern fans refuse acknowledge it exists). This show is excellent. The plot is dramatic, the characters are tragic and endearing, the fighting scenes are great, and it has the kind of reflections about humanity, love, duty, courage and sacrifice you only find in classic anime shows.
The animation is -obviously- of a different style than it is used in shows nowadays, but it is good: characters and backgrounds are detailed and colourful, the animation is fluid, everything looks like it should and I personally like the character design. However, I admit that if a watcher is not used to the seventies animation style the visuals can scare him or her away (although I keep saying it is not bad, just different).
Anyway, it is highly recomendable. 9/10