I first watched Tower of god with no expectation; it was just another anime announcement on an anime news website.
The first time I rate the anime was just based on that, the anime; however, my opinion completely changed after reading the manhwa. I know my opinion here needs to be based only on the anime. But, it is difficult to not make comparisons with the original source.
First of all:
Soundtrack: 10
The music, especially the ending and the ost on episode 9, are astonishing and impossible to forget.
Animation: 10
The animation is really good, completely different from SIU draws at the beginning of the manhwa. In other words, the animators have outdone the creator´s art concerning the first part of the story.
Characters: 10
All the characters are original and interesting, and the interactions between them are enjoyable to see.
Enjoyment: 10
It was really interesting and appealing.
The first episode was good, and the ones following it keeps on the same track. During episode 9, I decided to read the Manwha, and even though the art was messy, it was still utterly enjoyable. The author created a masterpiece without a doubt.
I decided to change my rate from 10 to 6 because, even though the adaption made a good job regarding the design of the characters, it is impossible to ignore the many changes and omissions made by the animation team, which basically destroyed any possibility of a second season.
Overall, 13 episodes were not enough to adapt the first part of this interesting story.