My friend suggested this to me: Absolutely no story. You get the message "Kill person X" then nothing. It's a semi-open world environment, your target is in a building in front of you, and you can choose how to get to him. Climb a building next to your target's and jump through a window, take out a guard, put on their clothes, sneak in, get close and stab him, snipe him, hijack a helicopter and fly it though the windows in the building and hit him, etc. Endless possibilities, absolutely no story except "Kill these people." THIS is how assassination games should be (in my opinion).