I initially had very little interest or knowledge of super robot animes. About all I knew was that Gundam exists and that was it. Then I got interested in Super Robot Wars (Original Generation, specifically) and when I decided to try some of the non-OG ones, I got interested in some of the various series that appear in said games. One such series that peaked my interest was Getter Robo, thanks to SRW A's rather prominent usage of Getter Robo. Story: There isn't too much of a story here. To be honest, I do not think it's really a strike against the show. It's reallyjust an excuse for Getter Robo to go beat up the monster of the week while the Getter Robo theme blares in the background. In short, it's awesome. However, as the show goes on, a certain pattern starts to develop involving characters introduced past the first few episodes which can get somewhat annoying as it falls into predictability.
9/10 for story, despite the fact there isn't really one. Until the last few episodes, anyway.

Art:
This is the second oldest anime I've watched as of the time I'm writing this, so I'm not too familiar with the "par" of 70s anime art. That said, it does what it needs to. Nothing is particularily busy or confusing, most likely because this was made before everything was done in a computer. A lot of frames and sequences get reused but like I said, not surprising considering its age and length.
7/10 - Nothing too outstanding, but not bad.

Sound:
This is one area where Getter Robo excels. It has an epic opening, an epic ending, and lots of great tunes and arrangements of the OP that play during the episode. The audio quality isn't the greatest, but well, it's going on 54 years old at this point. I usually skip the openings of animes because I don't like them all that often, but this was one show where skipping "Getter Robo!" would be a silly move.
9/10 - It's awesome.

Characters:
They're all decent enough, Musashi is often there to provide some comic relief before Monji and his robot are introduced, and well after they are. Ryoma and Hayato are the more serious ones, but even then, they still can joke around.
7/10 - They're good.

Enjoyment:
Could be because it's the first super robot anime I watched, but I had a great time. I just took it for what it is, a silly, hammy, 70s cartoon about high schoolers beating up dinosaurs. I don't think was a time where I was like "Oh yay. Time for Getter Robo..." so in very short: I liked it.
10/10 - I didn't try to take it too seriously. As one shouldn't.

Overall:
If one compares Getter Robo to more modern shows of any type, it's terrible. Tons of reused animation, a monster of the week format that becomes quite predictable, and so on. That is somewhat silly though, because Getter Robo didn't air in 2020, it aired in 1974. Expectations were different then and it's no surprise things have changed since then! It's good for it's time and personally, I think it's still good. Not everyone would agree though, haha.
9/10 - Enjoyable if you don't compare it to modern standards.