Is the dead man H?A?M? Presumably yes to all three
Is this taking place in the "real" world? no in a video game? yup, told 'ya this might go quick in another creative work (such as a novel, movie, etc.)? so no
Is he killed by accident? Murder? this is closest Manslaughter?
Does the strange face belong to his killer? yes Is it a human face? noish Animal face? no Face of some mythical being? no Is it a representation of a face? yessish Clock face? Rock face? Hieroglyphic face? Geometic face? but no to these