You are not an assassin in this game, you are a warrior.
This game should have been called anything except Assassin's Creed.
Your character is like spiderman. You stick on any surface, even an ice cliff... name it.
The parkour of this game isn't as good as in the other one. It's not fluid, and I'll say it is the worse, most basic, parkour they could have implemented.
The "assassinations" are just bad compare to the other game.
There isn't much discrete mission.
And I'll say it again, this game should have been called anything except Assassin's Creed. The story is great as a Viking warrior, and the gameplay is okay on the combat and action. But you are not an assassin, and that part of the game is just not great.
So, I am just disappointed.