Sangatsu no Lion is a completely pointless series, revolving around a few more than flat characters.
I'll try to be as spoiler free as possible while pointing out what I think worked and what not.
Story: 3
In a few words, the story in Sangatsu no Lion is "playing shogi". For as much as I would like to say that it talks about a kid growing, fighting his fears, learning how to relate to other people, eventually understanding how to live one's life, all of this is just barely touched, focusing more on "what if I moved the pawn in A7 instead of B2?". In 22 episodes, absolutely nothing relevant happens. No epiphanies, no events, no change, or if something happens, it's brushed off in an incredibly simplistic way.
We could think that since this is a Slice of Life, it reflects reality as it is, and oh, it does it perfectly. But please don't tell me that your usual, every day, routine lives are worth a series. Mine, is not.
Art: 6
For as much as I love shaft, the style here is pretty different from their usual. The colour palette, the watercolour-ish style, the animation itself were really pleasant to watch, as they give a warm vibe when it's needed, but doesn't work so well in the more "cold" scenes. Also, the classic shaft antics recur here as well, and maybe, they weren't so needed. What really bothers me here is the character design. From the beginning to the end of the series, the characters lose more and more punchiness and details, starting from a very specific character design (those mouths, really?) ending with a generic character from any other series of the last decade.
Sound: 5
Not much to say here
OTs and EDs are not so bad, but also not memorable. I finished the series half an hour ago and I already forgot what they sound like. Same goes for the background sounds and music. About the voices, the cast is galactic, it worked pretty well.
Characters: 3
Let's say you try to give an honest vote to your completely normal neighbour, or the guy that used to sit on the left corner in your classroom. That would be pretty hard, I imagine. The same goes here. The characters are completely normal people, but instead of having those many hues a normal person would have, they are just parodies of their "IRL" counterparts.
The MC is the usual "kind of problematic" character. Introvert, social issues, no friends, focused only on shogi. You keep watching him doing nothing, saying a lot of "I will whatever", then going back doing nothing. Just stupidly thinking about shogi. So much to forget to drink for days! Can you imagine that?
The female cast is the "obliviously-incredibly-good-and-sweet-girl-that-oh-so-love-to-help-you-for-whatever-reason-and-obviously-loves-sweets". As too often, the women in Sangatsu are put in the kitchen or related domestic areas, and those are the only moments in which you see them. Since it's a shogi anime, you could think there are also female shogi players, but no, the only one that you can see doesn't play anymore.
Is the rest of the cast worth mentioning? the fat but passionate kiddo, the cold and invincible player, the mentor, the blonde with weird haircut guy?
Enjoyment 3/ Overall 4
I think I said everything I had to, with very bad grammar and vocabulary, though, but since this anime has been so hyped up, I could not keep it in.
Sangatsu no Lion fails on every front. It fails in narrating a story, even a slice of life story, introducing elements that will be lost in the next scene, breaking tragedy or tension with out of place comedy, but still failing with both of them. It fails with its characters, with too good or too bad people that could exist in other genres, or using cliched characters that, as usual, follow the flow with no question asked. It also fails with the art, lowering the quality episode after episode.
So, there are a lot of way better anime out there. Go see them.