It's decent, but a large departure from the previous games.
You'll be doing a lot of levelling up in order to progress. Assassinations on more powerful enemies won't be guaranteed kills.
It's a lot more RPG-lite than the other games.
I think Odyssey was better, and very similar in structure. The only problem is it's so long I don't even want to look at another AC game for a while, and it was a few years ago that I played it. They all look very much the same now.