The original saw films were all fairly entertaining although I regard the first 2 are a step above the others. Jigsaw was a decent enough reboot and this a second attempt to reboot is fairly decent.
Firstly this is a fairly decent entry to the saw series. It features the usual sub par script and acting but let's be honest it's the story and traps that brings the viewers in and while this film only has few traps they are all rather gory as usual.
Worth watching but still nowhere near the quality of the first 2 films.
Given the pedigree of those involved in this sequel / reboot to the Saw cycle of horror films, you'd expect a bit more care to have been taken. As it is, it's probably the world's most expensive fan-made movie. This is Saw without the narrative invention, the smarts, or good ideas - instead we have a 'masterplansplaining' baddy, no suspense, bad acting, plotholes, no surprises and less gore. It's a shame as this was the film to draw fans back in but all it will do is provide a disservice to the earlier films. Bring back John Kramer (Tobin Bell) - this copycat killer was doing Kermit The Frog impressions (I wonder if Frank OZ provided uncredited voice work). Game Over.
Spiral is a 'Saw' movie in everything except name.
There's actually very little about it that's new. It has more humour, but that's about where the changes end. We still get characters being stalked & abducted only to come around in some horrific trap that requires them to maim themselves to survive (or requires others to get maimed to help). We still have an elusive killer uses puppets and imagery & saying they want to 'play a game' before rendering judgement on folks and telling them what has to be done to ensure survival. And we still have frustrated and badly flawed heroes trying to ineptly stop the carnage, all while the audience gets the impression that they might be too late.
Because people come to Saw movies for tension and inventive gore, we get lots of scenes of people trying to escape. The traps are quite hideous (one was so prolonged and disgusting that I did something I never do, and basically watched it through my fingers) and the gore is largely exceptional (apart from a few brief seconds of 'is it/isn't it realistic...?' that only momentarily distract). The plot, as usual, is silly and only exists to drive the gore and mutilations.
Meanwhile, Chris Rock is an interesting lead. Going full sweary in order to try to live up to the more serious tone of the movie, he puts in good effort, even getting a backstory as a 'rat' who turned on a corrupt partner in order to add conflict. Unfortunately despite some very likeable moments, he's simply not very convincing. Unlike many comedians, he doesn't seem suited to horror and drama at all. He constantly looks like he'd rather burst into laughter, and has no idea how to play a tense scene without looking manic and sweaty. Almost every dramatic scene he occupies is filled with URGENT SHOUTING (the trailer for the movie is actually a very good representation of how much he does this) and his relationships with his father and the partner he turned on are never remotely believable beyond being words on a script page.
For his part, Sam Jackson has played roles like this with his eyes closed, and near the end you start to get the feeling that he wishes he could do just that, working with almost no character development or material.
Max Minghella is a likeable, energetic presence as the rookie that Rock has to babysit as penance for some dubious actions (which would undoubtedly have gotten him fired from any precinct in the world, but hey...) and he helps give some of the scenes a heart that they would otherwise be missing.
In all, the writing is iffy. The direction is okay, but the director (series veteran Darren Lynn Bousman) seems uninterested in trying to shape the material into something better, aiming purely for the same kind of shocks and beats he hit during his earlier Saw films while upping the gore. His moviemaking history is filled with more duds than hits at this stage, so Spiral should be considered 'one of the better ones'. Writers Stolberg and Goldfinger should consider themselves luckier still that a script with this many stereotypical detectives making obvious stereotypical mistakes ever got made (clue; if it wasn't for the gore, this would've been thrown in somebody's shredder a long time ago) - especially with a mystery past scandal that is mentioned multiple times but a) never explained properly beyond a 1-line throwaway description, b) seems to be both ongoing in terms of behaviour but is always referred to as in the past (?!) and c) is so amorphous and vague that it's effects are never properly explained or shown.
Also, there's a plot hole the size of an aircraft carrier in a) how the killer is able to build his vicious instruments of torture and b) how they're able to get them into certain busy locations.
In short, it's a loud, gruesome distraction designed to prolong the franchise & if you're into gory thrillers, you're likely to enjoy this Saw renaissance.