Games in movies are usually depressing. Especially when the game becomes real, there is no restart, no extra life, no super power or anything, everything is reality. Once you are dead, you are dead.
The movie gamer is a good example. Actually it is pretty sad for people to get killed for the entertainment of others, it is like we return to the past, where killing is entertainment in gladiator. From here we can also see another game within movies, Gladiator. Most of the games within movies are cruel, as they involve death on reality. Unlike normal games where the character experiencing it all have no mind of its own. The game in movies involves real human experiencing real game scenes, and humans have mind, they experience fear, pain and desperation, which eventually leads to the human primal instict of survival, which isn't very nice.
The movie Saw and Battle Royale shows such scene effectively. It shows how desperation could eventually lead to human doing unthinkable horror.

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