I was waiting until Tower of God had finished to give my overall verdict on the show and what my thoughts were when watching it. Before I talk about anything my opinion is solely based on the anime alone and nothing from the Webtoon since I haven't read it at all.

To start off I really wasn't a fan of the art style (too minimalistic and lacking in depth & detail) but I know the art style was chosen to somewhat replicate the art from the source material which I can somewhat overlook and after a couple of episodes I got used to it. The thing I can't overlook was the terrible animation (I don't know if this was due to Crunchyroll's budget (highly doubtful since GOH looks a lot higher quality) for the show or the animation studio's (Telecom Animation) talent that handled TOG), all the fight scenes felt really flat and mediocre (except maybe the Yuri vs Yuga fight which didn't really have a lot of animation but felt more impactful and stronger than any of the other fights throughout the show).

Episodes 01 to 11 (and somewhat 12) feel very slow in terms of overall story development besides a few glimpses into side characters origins & scenes outside the tests. The show feels like it gives very limited information with only small little Easter eggs of information here and there to keep you hooked. Also while I got to better know certain characters and got the core logic/ dynamics of the series I still have tons of questions regarding a lot aspects of the series (I don't know if its better explained in the WebToon or in more expanded upon further down the line) such as how some characters seem like they originate from the world of the Tower (like Khun, Anaak, Endorsi etc.) where as characters like Bam, Shibisu, Serena feel like they were somewhat Isekaid into the world.

Episode 13 is definitely in my opinion the turning point of the show and really rewrites the shows character dynamics and what we presumed had actually happened. It is only until the story is flipped and seen from the perspective of Rachel that our main character had been chasing all this time that we have a true insight into the events that had unravelled and the kind of person she truly is (which I just loved). Also given the events of the final episode I now see what we have seen so far is the prologue to the main arc of the show (the actual climbing of the tower) and Bam getting his answers.

The best thing about TOG (the thing that got me interested & most excited about the show) was the OST composed by Kevin Penkin. Like Kevin's previous works (Shield Hero, Made in Abyss, Under the Dog etc.) the music is top notch and is the key element that really draws you into scenes and amplifies the show, to be honest if the anime didn't have his music I would of definitely rated the show lower since it feels like the shows really relies on the musical score to support it.

To conclude I do think the show was very overhyped from the start but despite having mixed feelings with the series I would like to see a Season 2 and continuation of the story (especially since I'm not a huge fan of manhwa/ webtoons for various reasons) and since the show was relatively popular I could definitely see that happening (there's enough content for another season looking at the WebToon). To be honest even at the end I still feel like Bam doesn't have much individuality as a character, he still feels very two dimensional and really only obsessing about Rachel was his main characteristic throughout the show (running around and being depressed like a dog who has lost their owner). Bam is also unfortunately yet another anime character that falls into the overpowered but doesn't know it trope which was rather a disappointing aspect of the show.

The design is a bit underwhelming. It looks cheap. Maybe not exactly cheap, but let's say simplistic, almost minimalist sometimes. And the colors all look a bit passed. It feels like something from 30 years ago instead of 3.

So I went to look back at the first episodes of the webtoon, and yeah, graphically it's a bit lacking, but come on, it's been 10 years, how the fuck do you decide to base your anime design on the first 10 episodes of a series that is at nearly 600 now ?!
The drawing improved a lot and it's gorgeous now. Why not use the current design and go for the oldest drawings ??

This is a huge disservice to the show and the original material.

Animation is not great either.

However it seems pretty much in line with the original story (or at least what I remember, it's been more than 10 years since I started). And the original concepts, the multiple characters and the complexity of the story (season 1 is not even the tip of the iceberg), more than make up for it.

Hope they continue, but one season every 4 years, it will be hard to catch up...
Why so long ? Specially as the production value looks pretty cheap, looks like something they could mass produce like animes from weekly mangas.
Unless it means they redesigned and improved the quality for season 2, which would be awesome.

I liked it during the first episodes, but towards the middle I started having doubts and during the last episodes I hated it.
My final personal opinion is that the anime is quite arrogant: it really tries to be kind of epic, but its characters are too shallow (or just don't match) compared to the complicated story (and I have doubts as well about the story itself - e.g. a lot of missing informations, too many sudden changes of directions, ...).
Potentially still worth to be watched, but be careful with your expectations.