A very old anime I watched it dubbed when I was barely 4 years old.
Considering the animation nowadays its animation is bad but if you checked all the animations at that time you will see that it`s actually pretty good and better than all the animes at that time.
It was dubbed in a lot of languages and I actually doubt you will find the original Japanese one easily if you want it.
I checked out the French , English and Arabic dub they were all very good and more importantly easy to understand even for little kids.
The story is about a guy who ran away from his planet and ended up on the earth later the people who invaded his planet tried to invade the earth but he drives grendizer and stop them as the time pass by his friends from earth join him and help fight the invaders.
The plot is very much like hero stories but you will find it different if you tried to check the evil characters are not always so evil sometimes they are just doing that because they need to help their own family or planet or whatever is important to them so the emotional conflict in the anime is a very good and complicated one and I guess it`s one of the reasons of its success.
Grendizer: What? And what for?
Gundam: Come on! You never run out of ammo or power! You pull out swords from all over your body and you shoot massive disintegrator beams! You are unable to use a normal rifle! You shoot your fists! YOUR. FISTS!
Gundam: And then all those impossible transformations and your approximate design! It is hard to understand even how you can bend your joints!
Grendizer (bending its forearm): Hey! It's right!
Gundam: Giant monsters and horrible aliens! Endless Fanservice! Incredible plot twists and collective laughter at sunset! Come on...!
Grendizer and Gundam: Hahahahahaha!
Grendizer: In short, you're envious...
Gundam': To die for!