Halo is unique. At a time when the military shooter genre was closed in terrestrial (or at best, mars) spaces, Halo presented natural environments filled with gorgeous alien architecture that presents an ancient mystery and a sense of wonder at the scale and the age of a place. Perfectly augmented by the monk-like vocalisations, Halo defies the conventions of military shooters by putting you in a beautiful place that you have to explore, and slowly come to understand.