So, I've watched some of the saw movies, and I noticed many similarities between it and none other than yugioh (or at leat select peices of the manga). Think back to when shadii (I think I spelled that right..its been a while) went around punishing people with the shadow games. The shadow games but someone in a situation where they have to figure out a puzzle or else they die. Now when you see the saw movies, the antagonist finds people who generally do bad things that hurt others (although, theres alway people there just for his enjoyment, but think to the way he got that guy who ruins the life of others because of his drug trafficking in saw 2, etc) and he gives them a puzzle to figure out or else they die. Of course on one side they have the good people testing the bad, and on the other we have a psycho killer doing it, but there are similar premises...you can figure it out and survive, or you die. I just thought that was interesting..take it as you will.