Pyramid game deals with the well-known school bullying. As if today's kids aren't already too creative in their methods of bullying, they have just given them another idea with this series.
Regardless, the series started intensely and interestingly, but soon they started messing with the timeline. Every episode is cut in key scenes and without any explanation why what is happening, the scene continues confusingly and without meaning. Cut scenes are returned sometimes in the middle or at the end of the episode, sometimes at the beginning of a new episode, and sometimes they completely forgot to return the scene to show what actually happened in the part that they deliberately did not show.
Overall, the series wouldn't have been so bad if they hadn't played too much with the timeline and thus made everything confusing.