It's a good combat game, but it's a GREAT stealth game. You can overcome everything without being sighted, or decapitate a soldier, throw the head to their mates and laugh at their screams while you launch a nuke of burning, explosive oil at them. The lore and aesthetic are gorgeous, but the best is the fact that the fate of Dunwall is decided for your actions and your actions only. It's easy to say killing is bad, but when you have been spotted, the novel guard is going to turn on the alarm and you've run out of sleep darts... what will you do?