First: to all those who try to fit it within the canon timeline. From my experience from anime movies, that's a pointless thing to do because these movies are not meant to be part of the series canon and therefore no need to analyze every bit of detail to find out where it fits.
Second: The plot which is the important thing. Sadly, this was the weakest thing for me. Prior to the release, we were told the story will be focused on Kurapika and Omokage. But Killua's subplot felt shoehorned in and I didn't like how Killua turned "yandere" for Gon and being intolerant to the idea of Gon having other friends besides him. Didn't they make other friends over the course of the series? Did Killua have any problem with any of them? No. So why make him so jealous when he first met Ritz? It felt out of character to me. Sadly this subplot took over the main plot of the movie and therefore we didn't see much of Kurapika and his problem! Even the Spiders who were supposed to have a bigger role where reduced to mere extras and saw nothing of them beyond Nobunaga and Machi against the dolls. And because they were strongly ignored it made their "surprise" raid at the end really forced! Not even Omokage and the Ritz who were the main characters of the movie were focused on. So in short, Killua's subplot is what made the plot weak and derailed the movie from it.
Third: The fighting scene were good, but if you're accustomed to Togashi's writing then you can tell if the fights were written by him or somebody else. Like the characters announcing their attacks. Obviously that's not what Togashi's been doing. There's also the mistake of making Uvo's Big Bang Impact an emitted attack instead of a destructive punch.
Though it's not the first time someone made such a mistake.
Fourth: Production. It's no surprise the animation is a tad different from the TV series, but there were a lot of moment that you can see how off-model it looks. Particularly on Gon! The second image is unforgivable! This is a big screen production and the long distance is not an excuse to draw something this weak drawing! And I don't know about you guys, but am I the only one who thought Ritz's eyes looked like they were drawn by
Ume Aoki? And the animation was sub par and wasn't the animation of a movie and was more like the typical animation of a TV episode!
So to conclude, the movie isn't outright terrible, but these issues affected it strongly and the movie may have gotten better if it wasn't for them.
7/10