Its Warhammer universe, cripled by Hollywood storytelling.
Difficulty is (again) quite easy - on hard, in first playthrough, I was killed twice in final battle. You have variety of melee weapons (hammer is awesome). Variety of clasical weapons - bolters, melta guns, plasma... Close fights are nice, combos, combined with stunning and finishers.
So why only 6,0? Can someone imagine a woman (!) lieutenant of Imperial Guard calling Capitan adeptus astartes by his first name? And later she tells him to fight with inquisition (in front of the inquisitor) and she lives... WTF? If the story would be more minimistic I would keep the game. Now its just for lending from a friend.
Im not mentioning the horrible pronunciation of latin names that only a few people is capable of.