Leviathan is an anime adaptation of Scott Westerfield's book going by the same name. Is it a good adaptation? Yes, but it inches very closely to just being "fine". Firstly, do I recommend the anime or book more? The book 100%. This adaptation made a lot of changes which doesn't properly close some plot setups and character arcs. The novel has a more pleasing story by the end. Back to the anime. I think the story is pretty good, considering it does adapt most of the good plots from the source material. There is always a soft spot inmy heart for historical fiction stories. We follow characters in a fictional World War 1 world, surrounded by "clankers(machinist)" and "darwinist(genetically enhanced creatures". It's a setting that definitely picks the interest of anyone who's into scifi.
The main characters are likeable enough, with just enough story for you to support their adventure. My only issue is race-swapping one of the main character which doesn't enhance the plot at all.

Next, the music for the opening and ending is pretty solid. Considering the great Hisaishi Joe worked on them in collaboration. The music to me is definitely one of the great parts of the show. Joe and company manage to to compose melodies that can trigger your emotions well.

Lastly, the animation. This is a 3D animation with a 2D style made by Orange who made Beastars. Personally, I think the animation is good enough. There are certainly beautiful moments accross the series, and also awkward parts sprinkled in between. So far, 3D animation with 2D style still needs some more improving.