Assassin's Creed has spent more than a decade flirting with post-release content concepts that are out-there enough to sell. There was an alternate timeline where George Washington was an evil tyrant. There was a whole add-on that revolved around first-person Animus platforming. We even got to murder as Jack the Ripper.
These are always novel. Assassin's Creed has always been about twisting history to fit the whims of a video game's story. These offshoot DLCs push that to an extreme, taking advantage of their tangential nature as carte blanche to try something wild. They usually work in an entertaining-but-forgettable way.
The latest one, The Curse of the Pharaohs, is the best yet.
via destructoid https://www.destructoid.com/review-assassin-s-creed-origins-the-curse-of-the-pharaohs-494627.phtml