I consider this as science fiction.
This is GoLion, the original Japanese dub of Lion Force Voltron, aka "Voltron III".
This is a far superior version from the HEAVILY censored version that was one of the first animes which fell victim to 1980's cartoon censorship/stupidity.
The differences are quite large.
1: The team are not a group of star explorers on a mercy mission to Arus, they were a group of explorers who were lucky enough to be away from Earth when the 3rd world war broke out and pretty much destroyed humanity, then the evil King Daibazaal and his mystical adviser Witch Honerva sent their forces to what's left of Earth to enslave the survivors. And the team gets captured.
2: The slaves are divided into 2 groups, the ones who are for hard labor and the others to fight gladiatorial games against Daibazaal's beast men. For the latter...those who lose the games are butchered into food for the beast men, the winners are allowed to live, or converted into beast men.
3: GoLion was a sentient robot that was able to take out many nasty monsters, but got so cocky that he challenged a Goddess to battle. She did not fight him, but said his over confidence would be his undoing, and broke him into 5 units, and he was lost in space for thousands of years, before landing on planet Altea (Arus).
4: The attack on Altea castle happened 15 years previous when Fala (Allura) was 1 year old, where as in Voltron, the attack seemed to have happened fairly recently, probably a few months or weeks. And Fala was raised by the old man this entire time.
5: Gore, lots of gore. Characters got killed, some very brutally.
Even as a kid, I KNEW stuff got cut out because the Voltron series was edited poorly, where one can tell stuff was cut out. Also, the dialogue was bad, some of it made no sense, and apart from B.J. Ward's sultry voice work, and that of Lothor and Zarkon, the voice acting was bad...double that when the guys had to do horrible falsetto for some of the female characters or kids. Also, robots don't eat, drink wine (sorry...
fruit juice 
), yawn, sleep, or shout in pain. When I was a 5 year old kid in 1984, I felt that I was patronized and talked down to, the censoring being so bad, and the stories feeling so dumbed down. The only thing the American dub had going for it was its soundtrack, and it being the first show to be aired in stereo, electronic appliance stores would switch on the TV's for sale when Voltron aired to demonstrate their, then new, TV's that had stereo sound to interested customers.
Enjoy https://www.youtube.com/watch?v=5Ux2aMNzbso
Also, the GoLion series lasted 52 episodes, BUT at the end of season one for Voltron, World Events Productions contracted TOEI animation studios, the ones that originally made GoLion and the other series that would be used as Vehicle Voltron, to make more episodes exclusive for Voltron and it's movie episode. The second season can be easily identified with new sound effects, the enemy troopers actually being robots (they actually blow up when shot, or showing exposed circuits, etc), and an alien chick who was in Vehicle Voltron seen alongside the Lion Team characters, and who was arranged to marry Lothor. The animation was also a little crisper and some new music was added in.
