I'm someone who is completely numb blood and gore from my years of watching it; I still love it, but it's hard to get scared anymore. This was something completely different than what I've been seeing these days I'm in love with the Saw franchise and will always praise it, but this just showed what a little bit can do overall.
Leigh Whannell felt very real with not only his numbness with life and going through it day by day, but when he makes it by the end, he felt the remorse and the horror of what happened
the filming also helps with how raw the environment was. it shows how clean or gritty the area is, it shows the boredom or the fear in David, and even when showing Billy, it feels scattered yet put together.
I think they also did a good job not showing the gore besides blood. as much as I'm used to the gore and splatter from the movies, this just felt right and the fact that it's minimal just helps focus on David and his will to live rather than focus on that it's a bloody scene
I recommend watching this for it's gritty and pure horror; but if you're watching cause you're a Saw fan, then I commend you for enjoying something as much as I do