The Notre Dame was modeled on a 1:1 scale. It was created by one employee and took them over 8 months to create. The model was so accurate that Ubisoft turned its data over to France to help repair the real Notre Dame after a devastating fire in 2019.
The first installment to feature a multiple armor classification system. Which means that you can customize your assassin in any way you want.
The Dead Kings DLC was made free to everyone as compensation for the game's rocky release being riddled with bugs, glitches, and frame rate issues. People who had bought the season pass also got a free digital copy of a UbiSoft game on Xbox One or PlayStation 4 of their choosing.
The game was in development for 4 years.
The parkour and combat systems were completely reworked for this game.