I mentioned it in my original post, but I really want to single out the Halo 3: Believe ad campaign for engaging in a kind of emotional manipulation that I, as a actual veteran, find particularly distasteful.
The ad campaign is centered around a “Museum of Humanity” and a number of interviews with actors portraying elderly veterans. These veterans recollect their time in service alongside Master Chief: serving in the same battles, having their life saved by him, and recollecting a time when their unit waited in the dark for their savior’s arrival (@7:45).

Even though I find this distasteful and manipulative, I must admit this is a very effective ad campaign (after all, I’m still thinking about it 15 years later). The slight of hand here is that YOU the viewer are invited to imagine yourself as Master Chief, to give YOU the feeling that by playing the game you have served with these men, that possibly without YOU playing, they would not be alive to tell their stories. By setting these tales in the past, it almost implies that by NOT playing, YOU would be letting these people down, they will wait in the darkness and YOU will never arrive to save them. The war documentary conceit gives the stories the gravitas of an actual historical event, and allows you to imagine that decades later, people whose lives depended on you will still be recounting your Halo 3 exploits in hushed, reverent tones.
I’ve got other issues with the juvenile way the Halo series depicts military service, particularly the way it depicts women (when we live in a world where sexual misconduct is rife in the armed services), but my critique is frustrated by the winking way that the Halo series usually invites you to not take it seriously because it KNOWS it’s an adolescent wish fulfillment cartoon (except when it wants you to take it seriously, like with this deadpan Believe ad campaign, which is partly why these ads leave such a bad taste in my mouth).