Is there difference between the manga and anime version, yes few, but anime was done quite well that you do not notice those changes.
Story is not changed much and progress nicely, its not slow or fast. Be advised that this 12 episodes cover only first 4 volumes (and first part of 5th one). But they did it great.
Art is quite good, i was surprised. From house and forrests to characters, they bring everything into life with style they used. There is no lose of quality in it, from 1 to 12th episode it was great.
They did quite well with sound and there was intense moments (more then one) where sound did a great job. One thing i really like in The Promised Neverland is characters. Characters were beautifully done, especially Norman, Emma, Ray and Isabella. While Isabella may be seen as antagonist in the series, she is same as those kids and she of course know much more then kids did. I fully understand her actions, and no matter how you would see it as bad, she did everything to give those kids best lives she could. All other characters were quite okay.
I did enjoy this series, loved the manga and love the anime. It is beautifully done. Not all anime adaptations end to be good. I find strange that they chose female voice actors for Norman and Ray. Ok maybe it work for Norman but for Ray no. Mariya Ise did good job with Ray, but on some points her more girly voice appears although for short moments. So it would be better if male actor was chosen like for Don.
Is it worth to watch?, Yeah, if you like manga, you will probably like anime adaptation as well. Taking also that second season is to be released in 2020 (which is probably to cover rest of volume 5 and up to volumes 8-9) i guess we can even think of season 3 in future. It is excellent series and worth to watch and read.
