1 It was translated to arabic
Grendizer was translated to Arabic, the main spoken language in the middle east, and broadcasted on many middle eastern TV channels. People at the middle east were able to relate to it very fast because of the language, so many people loved it.
2 The theme song was extremely catchy
The theme song appealed greatly to people, especially after it was translated to Arabic. Many considered the Grendizer theme song motivating and uplifiting.
3 Kids connected to the characters
The show was very popular on Middle eastern TV channels, many kids grew up watching it. As a result, Kids connected with the characters and the cartoon.
4 Kids want to be strong
Grendizer is a perceived as a strong robot controlled by a human. The way the robot moved and looked made it symbol of power and strength. Because all kids want to be strong and powerful, they fell in love with Grendizer.
5 It had some great soundtracks
So many people loved the great soundtracks of the cartoon. Some people used to watch the episodes to anticipate the moment when the pleasant music is played.
6 The human characters were relatable
Grendizer isn't just about robots, it features heroic human characters such as Kouji and Daisuke. Kids found the human characters relatable, heroic, brave and strong. One of the main reasons Grendizer became popular is it's unique character selection.
7 Teaches positve values
Grendizer isn't just an aimless cartoon but it teaches people good and positive values such as dignity, loyalty, love and trust. This gave the cartoon a deeper meaning and made it appeal more to people. (See Why Mr Bean is popular?)
8 Embraced by adults
Grendizer wasn't just favoured by kids, but some adults like it too. It isn't uncommon for an adult to watch Grendizer, especially if he used to watch it as a kid.
9 It's funny
Grendizer cartoon isn't all about being serious. There are some funny characters such as Banta & Dambi and lots of funny situations that add a good sense of humour to the cartoon.
10 Males love robots
Males love robots. Grendizer had a very wide variety of robots and enemies. The fact that a human controls each robot makes the cartoon more appealing to people since they can relate to those humans. (See Why some people like Grey’s Anatomy?)