The gorefest the series is known about.
This has a much bigger budget than the original Saw, so they used the resources to have a bigger cast stuck in house filled with death traps. If they cooperate they might be able to survive, but of course they don’t because they have secrets that make them hate each other. This is all neatly revealed in the final flashbacks, and since it introduces new information, there is no way you could piece something out from the start.
Unfortunately, this turns the film into a different genre. Each character in now cannon fodder, just a bunch of people that need to die so that the can renew the cast between sequels.
The plot also goes to ridiculous lengths to connect this to the last film, and that puts some strain on suspension of disbelief. Not that having people survive getting thrown into a pool of used needles is realistic.