The levels are so atmospheric and diverse, and provide extensive options for handling situations in your own way. In both my low chaos and high chaos playthroughs, I never felt 'funnelled' into a specific path or action, and was always able to find creative ways to conquer a specific obstacle.
The game felt very reminiscent of Bioshock (which is a great thing in my opinion) and I believe that was largely due to the incredible atmosphere and level diversity presented.
Thanks a lot, all of you!