Now, time for me to dump on one my of favorite series.
Assassin's Creed Origins: I enjoyed this game despite it's flaws but one point annoyed the crap out of me. So I really liked how you could enter the pyramids/tombs and explore them in search of treasure and such. What bugged me is that 1.) you got into said pyramids and tombs because almost all of them have big honking holes in them, 2.) Almost all of them are still stacked with stuff(including valuables) and 3.) Bayek is okay with what's essentially graverobbing.
While I admit I'm not an egyptologist or archaeologist, this bothers me because:
1.) The Pyramids were ancient in Bayek's time and most of them had long since been broken into and robbed. This was a known thing and was one of the reasons the Pharaohs stopped building pyramids at all and started building hidden tombs in the Valley of Kings(which still didn't stop them from being robbed). And this happened LONG before the Romans got there in the 1st century BCE. To make it worse, you can actually enter King Tut's tomb in the DLC, which was one of the few NOT robbed considering it was completely intact when it was discovered in the 1920's.
2.) Despite having these big tomb robber sized holes in all of the tombs, most of them are remarkably intact and you can still find loot them them(which makes it look like the robbers just made a big hole and left without actually taking anything).
3.) Bayek is portrayed as being very pious and religious and at one point in the intro says he's uncomfortable stealing from a tomb. Which doesn't seem to matter at all in the rest of the game, when you actually have to enter several tombs(including the great pyramid) to advance the story.
On a similar note, The battle of the Nile took place in 47 BCE. There's like one more stretch of gameplay after this and then Aya takes a ship to Rome to Assassinate Ceaser in 44 BCE. Once she gets on the ship there's a years-long time skip that seems only to put Aya in Rome in time for the Assassination with no explanation why it took so long to get from Egypt to Rome. Yes, I realize travel took longer using Ancient ships but not THAT long. A cursory net search says an ancient ship could have made it from Alexandria to Ostia(near Rome) in about a week or two using established trade routes across the med. So Aya was apparently taking the scenic route for those 2-3 years.
AC Odyssey: I'm gonna keep this one short because I went over a lot of this in my big "I played through AC Odyssey" threat in the V1 forums and I bitched more then enough about a lot more over there(that thread went on for a while) In the "Legacy of the First Blade" DLC, the ending has Kassandra's child sent to Egypt to keep him away from the Order of the Ancients(which ironically is a place they're very active, though I'll let that slide). What bugs me about this? During the ending cutscene for the DLC, they show the child and his descendents eventually lead to Aya from Origins, but in the background you see the Pyramids being built. I realize it's dramatic license but Odyssey takes place in 400ish BCE. The Pyramids were built around 2500ish BCE AKA were already 2000 years old when Ancient Greece was in it's Classical period. Really Ubisoft? Really?
Also, the ship mounted flamethrower in the same DLC. No, not even close. I let the Mortar in Black Flag slide because it was period appropriate and a fun gameplay mechanic but the flamethrower thing isn't remotely close to feasible or accurate to the time period.
AC Syndicate: So this bothers me partially because it never gets brought up and partially because it violates one of the fundamental rules of the series. Until AC Origins, it was assumed that to see people's memories in the Animus, you had to have a line of descent of some sort(so to see George Washington's life from his POV, you'd have to find one of his grandkids, but since he didn't have any biological kids, that would be a problem). Revelations kind of got around this using the discs which work as memory recorders(so Ezio could see Altairs Life and thus Desmond could through him).
Syndicate didn't even bother, which is why you can play as both the Frye Twins despite Evie apparently not ever having had kids(Lydia was Jacob's granddaughter) and this is never really explained. Even worse, however, is the fact there's a couple of cutscenes where the big bad Templar, Crawford Starrick, is talking with his minions alone in his office. Which is kind of a problem because we're not seeing Crawfords DNA, we're seeing presumably Jacob/Evies and there's no hint how we have access to Crawfords Memories. The game just assumes we do and goes along with that because they needed the villian to exposit.
I suspect this is why Origins built in a bypass of the new animus just needing some DNA, which can be plugged in from the corpse itself(or a couple flakes from a piece of eden).