Again, I enjoyed it. That's Higurashi enjoyment, admittedly, so you'd be disappointed to miss a disturbing, gruesome end. Nonetheless it's serious, mostly faithful and a good Higurashi adaptation. Stuff I liked includes:
(a) Ren Osugi as the policeman Ooishi. (Just to prove they didn't shoot these films back-to-back, there's a recasting.) I've always loved Osugi. I quite liked Tetta Sugimoto in the 2008 film, but it's a joy to see Osugi here.
(b) Airi Matsuyama as Rena Ryuuguu. She's cute and adorable, but she can do scary cleaver scenes.
(c) It sticks closely to the original (the "Atonement" arc). Pacing, tone and nastiness are all what they should be. It doesn't rush and it doesn't think it knows better than the source material. My only niggle is some heavy-handedness in the portrayal of Miyo Takano, although admittedly it's effective in this narrow context. This film was the last in its short series, so we shouldn't care about how the story unfolds later. Nonetheless, I'd suggest comparing with this film's portrayal of Rena's father's girlfriend to see a subtler use of character layers.
(d) The roaringly bleak ending.
(e) I like what Ataru Oikawa did as the writer/director. He's directed J-horror elsewhere, e.g. Apartment 1303 and the Tomie series. I'd call this proper J-horror too and a good deal better than a lot of its rivals. Japanese manga/anime live-action adaptations have an indifferent track record, but he's done well and I never thought this was a second-best version of the story. It measures up.
I like Oikawa's use of surrealism, with disorientating light and camera angles. It's extreme, but he commits to it. The film's combining some wildly unnaturalistic visuals with that understated J-horror naturalism, which is interesting. Oikawa's also comfortable with Higurashi's different tones, from playfulness to grand guignol. He uses lots of child actors, but they're never a problem. Seriously, I'm impressed. I think he's done a good job with difficult material. I'm tempted to watch more of his work now, despite only liking Beginning out of his three Tomie films.
Airi Matsuyama (Rena) and Rin Asuka (Mion) are reunited in Hideo Nakata's 2019 film, The Woman Who Keeps a Murderer. Hmmmm. I might go looking for that.
The film works. It won't give you all the answers, but it's the end of the anime's first season and a satisfying, logical continuation of the 2008 film. It's a shame they didn't make more. It fits nicely into the greater Higurashi framework, e.g. giving us what's clearly a Shion scene, even though the film leaves it up to us to put the clues together. I also liked the cast, e.g. Kotaru Tanaka suddenly making Irie-sensei charming when it comes to his baseball team, despite minimal screen time. I still like the core cast.
Are these two films worth watching for Higurashi newbies? Mmmmm... maybe. You'll only be seeing important fragments of the whole. You'll miss the revelations and developments in the series's second half. You'll be confused. However I did enjoy these two films, so maybe they'd work. They even tempted me into watching the 2016 TV series, which was a mistake.
Don't expect a happy ending, though. Well, sort of. It is and it really, really isn't.