I'm only a few hours in the game after picking it up on Steam.
I have an "Older" gaming laptop with a 970m and I7-4710hq. The CPU bottlenecking made this game very hard to set the graphics right to be beautiful and steady FPS. After hours of messing around, I finally got it to 40fps steady on mostly High setting with rarely any dips under 30fps, but we'll see what happens when I get to Athens as some people have said it's a killer.
Anyway, having played all the AC games and finishing all of them except Unity (I gave up and never went back after patches), and being a huge fan of history, I adore the story. Funny thing is, I always wondered how the Assassins came to have Eagle Vision, or other special powers that were not explained by the Apple of Eden. Always figured it had something to do with the Isu, but I had always hope they would go deeper in explaining this.
We I'm getting to learn more with Odyssey as the game goes even further in time getting closer to the story of the ISU themselves. So as far as a story, to me, it doesn't need to be only assassins and brotherhoods, Assassins Creed is a game title, the story can take it where ever it chooses and I will follow!
Gameplay is great as it's very similar to one of my all time favorites in the Witcher 3. I'll figure the game out more as I go but I definitely like it so far. The fighting is still a lot of button mash even though it's not as bad as origins. The perry, roll, and 4 "spells" is nice to have. Still I feel like something is missing. Being able to upgrade the boat is fun. I had so much fun with Blackflag even after 100% completion. I'm seeing the same potential here.
I see a lot of negative comments about this game and series, but I got it on steam for $30. It will likely give me 100hours of fun. Whether it's perfect or not, I don't think there's a better value for fun anywhere else.