These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Each and every single one of the Circle's leaders.
George Edwardson, Nanib's superior in India. After Nanib convinces some rebels to stop fighting and go home, Edwardson ambushes them and then happily praises Nanib for sending them into his trap. His callous disregard for the Indian people makes it clear from the beginning that he's a bad guy.
Critical Research Failure: The model of the Mediterranean Home City Cathedral is based on Florence's, despite that none of the Home Cities available are called "Florence". (Or any other Italian city for that matter)
Good luck trying to find a Catholic Cathedral resembling St. Paul's in Amsterdam.
Game Breaker: The Sioux Rifle Rider. They have the same bonuses as melee cavalry but they can attack from a distance.
Moral Event Horizon: In Shadow, Chayton was tracking down Crazy Horse in an attempt to negotiate peace between the Sioux and the settlers. Holme trails him and attempts to assassinate Crazy Horse, completely wrecking any chance for peace between the settlers and the Sioux, so he could take the gold from the Sioux.
Scrappy Mechanic: Most players avoid naval-oriented maps altogether due to Arbitrary Headcount Limits on each ship type and the incredible strain watching a naval battle puts on most low-to-middle-end computers. A later patch fixes the performance issues with naval units, but the mortar/monitor/rocket shell explosions will still put a strain on low-end PCs.