I still long for a day when it is the Dark Angels who get their very own game, smiting heretics for the Emperor.
Dawn of Racing II: GORKAMORKA
Also, interesting 40k video game fact - there was in fact going to be a Gorkamorka video game years ago on the Dreamcast and it was going to be a vehicle combat heavy game with touted features including being able to harpoon rival vehicles, as well as a random chance of the skorcha blowing up. The game was scrapped because the developers realised that the Dreamcast had been all but abandoned by Sony, so of course we'll never know if that's how things would end up.
Anyway, point being, while the games are being made by a third party, ultimately it would be Games-Workshop dictating the tone and content of the game. Even if there is a degree of gravitas to the game, its only because the setting itself is so GRIMDARK, which is in itself so damn cheesy.