I don't have access to the full book, but from what I've seen so far and judging by the author's comments on his homepage... the marines are actually wargaming running military combat simulations. On tables. With miniatures. Iron Warriors-style.
...Yes, the Smurfs are playing Warhammer.
ProxyPull yourself together, 1st Company Captain!We were wiped out to the last man...What are yer babbling on about!We're tied on victory points with the other army!You have fought well against those frakking sons of groxes!utterly and ruthlessly defeated...We shall erect a statue there in honour of the valiant effort of 1st Company!And I shall pledge an oath, on that very statue...Ughh... Chaplain Cassius...Behold!!Ou... Our statue...that I will protect Macragge without fail and see the Tyranids defeated!!shakeRight!!I... I am deeply sorry...wheezewheeze