Spoilers.
I am dumbstruck at the stupidity of characters, poor acting, and unrealistic plot line.
The main actor was so fake the entire time.
The stupidity of these characters was astounding. The lead had next to no empathy for even his deepest friends. The Russian stereotype is way overplayed and hardly realistic.
There were so many red flags in the game that were seen by every character except the main until the absolute last second.
His friends are in torture devices actually being tortured and he laughs.
And then we are supposed to believe that he snaps and kills someone after they're tortured "for real"?? That kind of whiplash from the same stimulant is unrealistic.
This movies plot is unrealistic to begin with. What friends would play a "prank" to the lengths that they fake their own deaths, in a foreign country, after an initial traumatic prank. There's crossing a line, then there's driving a mile past it like these "friends" were doing. If they did have reason for a parable this intense, it was not made clear in the film.