I liked it a good deal. I particularly enjoyed Ryunosuke Kamiki's performance in the lead role, which could make me laugh with a microreaction. He's nailed it. Our protagonist, Kiriyama Rei, is after all a borderline autistic shougi genius who finds it hard to show emotions and talk to people. He's a blank face buried under thick glasses and helmet-like hair. The whole point of the character is that almost nothing gets past his facade.
Kamiki, though, makes him a delight to watch. I'd be laughing at something as tiny as a surprised facial expression, or a determined line delivery that's not quite in tune with the people he's talking to. He's the reason to watch these films. They'd have still been good without him, but Kamiki quietly lifts them to another level. I can imagine rewatching them one day, basically for him, and I'm tempted now to start hunting down his performances in other films. What else has he done? Ahhh, voice work in some surprisingly high-profile anime films: Your Name, Arrietty, Summer Wars, Howl's Moving Castle, Mary and the Witch's Flower, etc. all the way back to Spirited Away in 2001. He was also in the live-action Rurouni Kenshin films, which incidentally had these films' director.
Even apart from him, though, there's still plenty to like here. The film works. It's really long, but it doesn't feel that way. I liked all the cast, I happily watched it all and I'd have watched a third film had one existed.
The only slightly disappointing bit is the bullying subplot, which isn't anyone's fault but is simply due to reduced screen time. I wouldn't dream of calling it bad, but it's also not as strong as the anime version. In comparison, this version's been compressed. There's less detailed discussion with that teacher of anti-bullying measures, for instance. Rei doesn't go to see Hina in Kyoto. The horror doesn't and can't go on as long as it did in a 44-episode TV series. It thus doesn't have the same weight... but it's still a perfectly good piece of filmmaking, with strong scenes.
I realised I was wrong about something in my review of the first film, incidentally. Not all the "orphans" are orphans. An absent father returns, although unfortunately he's the kind of shady character who might have been better staying away. Personally, I think these two films are about family. Fathers, daughters, sons. Sometimes they're dead and sometimes they're bad. It's tragic to realise how much the Kouda siblings really had loved shougi. Gotou is both sympathetic and a monster. Rei never truly escapes from his adopted family, whereas I'd got the impression that he mostly had in the anime.
Oh, and Kana Kurashina is still utterly beautiful as Akari Kawamoto.
The film is Kamiki's, though. He owns it, as Rei. I love the way he's so clear and perceptive against Yusuke Iseya's Seijiro, for instance, until he takes it too far because he still only half-understands this "other human beings" thing. He's an absolute wreck in his match with Gotou. He's funny. This film series would probably be a fairly hard sell to general audiences, being 5+ hours about a introvert playing Japanese chess. It could easily have been boring, but I enjoyed it all and and I'd happily watch the whole thing again. I'd recommend it.