Not sure what to say...

I'll start from the top, while this may be an erratic kind of review, I would still like to say something about this show.

Face Value

The face value of BNA (character designs, voice actors, OST, etc.) is very well done. The colors in the show even give off the futuristic vibe in which Beastmen and Humans are allowed to live together, and really emphasize that this is set in the future. I really enjoy the art and work put into the animation, it's well done and even has some cool fighting scenes with Shirou Ogami and other villains. The art style is what (in my opinion) carries the entire show forward. The art is attractive and yet cool as well.

One problem that I do agree with this however is that there are definitely recurring themes of overused music, such as the ending and the song "Farewell" from the official OST. These two songs were stuck in my head, but not in a good way. When I had heard them play throughout the show, there were moments when I had cringed and just made a face towards it. The music became a not-so-subtle way to show sadness or regrets and instead became a nuisance.

The Story
I would generally say that as the show went on, Michiru was losing depth in her own character. We understood that after a certain point, she had

Spoiler, click to view

gained the ability to adapt to her surroundings

but despite all that, she stayed the same throughout without even minor adjustments. She should have the most consistent storyline but even then, it seems so empty.

The content of the show is mostly a "free roam" kind of storyline, where there is an arc overarching the entire show, but it isn't revealed until later on.

Spoiler, click to view

From the moment when Nazuna is introduced into the show, it seems clear that there isn't much of the story besides someone going into the Anima city. While before the shit that happens towards the end is really mostly explaining a majority of the characters that will LEAD up to the ending, it wasn't very creative, and there were sparks where they could've taken the story. Alongside this, the explanation of how Michiru's power works aren't very clear and make us as the viewer thinks for ourselves. While I was definitely confused at first, I think it would've been better for her to have almost a "training arc" (maybe that would've ruined the whole show though LOL). One in which she discovers her innate ability to adapt, but I can see why that would also make everything bland and vague.

Thoughts

I really want to give it a higher score, but the ending and towards closer to the ending doesn't allow me to.

This is a pretty vague review and everything I may have said might have not just made sense, but just watch the show. I think it's very good even with some emptiness and gaps in the story, but as is most 12 episode long shows, they usually do have that effect. Compared to other shows, it's very unique in its own way and definitely is able to enrapture you with its colorful art style, funny and witty scenes, and overall lovability of the characters. It's worth a watch.