I read an article about this game a while back, but I never bothered to download it because the premise disgusted me. Games are meant to be pleasurable, not to explain something like a massacre. There are news articles for things like that.
It's worse than a war game, because most often war games will put you on the "good guys" team, you may have justice in mind, and you're playing with anonymous characters, anyway. The guy that made this game used all of the real peoples' names and faces, even used quotes. How do you think the families of the victims of such a tragedy would feel if they knew their deceased relatives were being put into a game like this?