4. Friendships
Roughly the same number of children compete in each films battle to the death, but their relationships to each other are strikingly different. By which I mean, in Battle Royale, the children actually have relationships to each other. In The Hungers Games, 2 children are chosen from each of 12 districts to compete. Which means that only one of their opponents is someone they may have met before, and the rest are strangers. The two lead protagonists in the film have seen each other, but never spoken. In Battle Royale, all but two of the children are all from the same class in school, they have known each other for years, and they have histories and interconnections with each other which are revealed to the audience as the film progresses. Their coupling together is the result of an actual long-standing affection for each other, and is not merely a feigned-romance for the purpose of survival.
Obviously, the prospect of being forced to kill to survive is itself terrifying. But being forced to kill your own friends, your own actual love makes the emotional stakes even higher. For following its premise to its logical conclusion, Battle Royale wins another point.