A couple of reviewers that, judging by the date their reviews were written versus the airing dates of the episodes, judge this little series to be a simple and childish tear-jerker, should have probably stuck around a little longer to actually give the show a chance to shine.
Because, having just finished all 11 episodes currently out, it really does shine. The first two episodes do indeed come across as slightly formulaic and simplistic sob stories (though necessary to explain the actions and motivations of our two main characters), but then the show takes a sharp turn towards political intrigue and thick, swiftly-paced, plot-heavy storytelling.
A simple underdog/rise-to-power shounen plot evolves into a complex chess-board of feudal power plays featuring a large number of independent players, and many characters who initially seem to fit trite and well-trodden stereotypes turn out to not be that at all. There is no simple black and white morality here - except perhaps for our protagonist, who is a pure cinammon roll. Characters have complex motivations, contradictory feelings, regrets, secrets.
The animation, seemingly simple as it is, permits examplary fluidity and expressiveness. Instead of reserving "sakuga" (effort-dense, impressive, highly fluid animation style) only for combat, here you get sakuga of crying, sakuga of hopping about, sakuga of someone collapsing in despair. I will take this unique, interesting and fluid style over the jittery mouth-flapping 3-d models that are becoming the norm in the anime industry any day. The sound and music is good, too - though nothing astonishing, on the level of, let's say, Made in Abyss.
As a mother myself, I was also very happy to see complex and well-written mother characters, that are neither the one-dimensional "good parent" curdboard cut-out, or the evil shrill hag, but human beings with their own complex thoughts, emotions, secrets and agency. What a rare treat.
Lastly, with the protagonist being disabled (abnormally low muscle tone, deaf and mute, and heavily coded as autistic though that is not outright stated) there could have been a lot there to make me cringe. Either romanticizing the disabilities, or magically curing them, or pretending that life wouldn't be hard for one who has them, or going for cheap inspirational "just try very hard and it will be fine". Despite a touch of that last one, the series actually handles disability surprisingly well, though - showing both moments of despair and triumph, discrimination and understanding, extreme protectiveness and extreme faith, and gracefully landing somewhere in the middle overall. A disability is a very real and often immovable obstacle, but it's also neither a tragedy, nor does it subtract from one's worth.
I remove a star for the slightly heavy-handed, simplistic tear-jerking of the first two episodes, but have nothing else to criticize, really. Hooked, and waiting for more.