This game is for the patient!
The game definitely caters to and rewards the patient player. Take your time to monitor patrol paths, listen to conversations between guards, and take your time planning your attack. The missions are fairly linear, but each guard encounter is in itself a puzzle. Find the shadows, know where you can sneak without being seen, know how long you have before the NPC moves/turns so you can time your kill perfectly. There's a lot of story and foreshadowing in guard conversations, take your time to listen to all of them to get the full experience. If you rush through this game, you'll definitely finish it feeling underwhelmed.
If all of that that isn't appealing to you, you definitely wont enjoy it. If it is, you should have a great time plotting your way through the difficult missions, enjoying executing your kills perfectly.