Perfect directing and tension thriller. I missed something, but it was great

Rating: 8/10 (12 July 2019)

Imagination to use every single way to create tension through the movie in every single scene (once the action starts).
The movie is short and doesn't try to do more than it should. And that's not a bad thing, and makes the movie really good, but also doesn't make it a 10.
There are some twists (little twists), and the first one comes too early. The characters are beyond shallow, which again, it doesn't "really" matter, but could've used just a bit more depth. There is no point, really. Not even a thin one.
Saw: Revenge; Serial Killer with an ideology; Irony of life (survives a suicide attempt, yet the cancer can't be cured).
Last House on the Left; Spit over your Grave: Over the top Revenge against sexual crimes.
Cube: Twisted social experiment
What's the point of the movie? It's about something? Again, even a thin theme or idea?
It's really good, but it's so shallow I can't consider this one more than that