As a big fan of the first two it was painful seeing how the series declined starting with three. By the time Origins came out I had given up on another Assassin's Creed being worth the money, and maybe played Origins for an hour or two before bringing it right back and planning on not picking up another one. Then my boss got me a copy of Odyssey, and after dragging my feet I finally tried it out.
Imagine if your favorite Assassin's Creed did a Morrowind (Old Xbox version) mashup, but also gave you optional access to Black Flag's ship. The reason I say Morrowind and not Skyrim is for both the lack of dragons, and speaking for myself, while there's definitely a story, the game doesn't force it on you and let's you do your own thing. There was a negative moment in my travels, somewhere on an island to the east of the map, I had to hop back into the story only because the Spartan kick and the coolest assassination techniques were locked behind a certain point in the story. Which fortunately was where I was at, but still kinda annoying, even if I understand they'd make you a tad more overpowered. Not to say there is such a thing, each continent is clearly labeled with a suggested level, and the clever can still thrive in areas two or three levels higher than them. I haven't confirmed it 100%, but it seems to me some areas match your level despite what the map says, which is good if true since the game would make the enemies seem as though you're kicking puppies if it didn't.
Awesome game, ain't like the old ones, but they definitely got the right idea now.