Ionami said:
Just really wasn't anything about him (Niko) I could relate to, or really like.
That's true of anyone who's killed a human being. The majority of gamers probably don't understand the typical human response to murdering someone.
The point of GTAIV's characters was to illustrate the kind of choices these characters made with their lives, how society tied them up in a high spot then cut the strings. Niko is basically the ultimate example of this; he's been destroyed inside by the murders he's committed.
This makes him superior to CJ and Tommy, neither of which showed any truly human response to suffering, particularly since within game parameters there is a real potential to be someone extremely harmful to the city, killing vast numbers of innocent people. GTAIV is making an actual comment on Western society through Niko, adding layers of meaning to the game.
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It comes down to what you seek when you play games. You might want meaning, or you might want fun. It's unrealistic for any of us to expect others to want what we want. But what makes GTAIV so captivating is that it allows many of us to have one or the other, particularly since it is designed in an incredibly convenient fashion.