Thinking about a Killzone movie, I keep thinking about another videogame I'd like to see, that might NOT actually suck, DEVIL MAY CRY!
I think it could be done in the same mold as the Blade trilogy, (R-Rated, horror-action) being that's what the story steals from anyways. It's very similar in it's basic premise (guy who's half human, half superhuman being wearing a trenchcoat uses guns, a sword and superpowers to fight other superhuman beings).
Where Blade is grounded in reality, DMC is based more in fantasy with demons and the devil in hell. WHAT'S THE MOVEMENT SAY?