Gosh, there are so many really overly literal people on these boards. Scholar Richard Middleton discusses that the songs that have the most success and longevity are what he calls "undercoded." This means there is room for interpretation allowing more listeners to have a connection to the work. Overcoded songs are too literal and too obvious and don't generally stand the test of time.
Clearly, Ms. Mayes made a connection between playing Halo: Reach and the speech at Mandela's inauguration. This connection seems to be related to the musings (this is Mayes Muses, after all) that seem to be important to her: power (where we get it, what we do with it) in relation to violent games, the urge towards heroism, relationships to violence, where/how we get feelings of accomplishment.
Anyway, this song is about Halo. But it isn't about, "Oh, on this level this thing happens, let me put it in a song." It is more a meditation on Halo as a game and as a cultural and interpersonal phenomenon. And that is what makes the song art.
I think this particular song is of a piece with musings like: Modern Warfare, The Machine, The Mirror, and Overlord. Anyway, good job Ms. Mayes, I'm looking forward to the next installment.