4. Speaking of violence, it’s a total rip-off of Battle Royale – Well, not a total rip-off. But there are enough similarities to call shenanigans. The 1999 Japanese novel and 2000 film also features kids forced to kill each other while the world awaits the victor. But the part about it being a rip off is not bad at all! Battle Royale became an instant classic and featured some of the most disturbing sequences on screen featuring teenagers. If that’s the original  source material, then BR fans can just think of it as a milder, pseudo-sequel.