I've completed Assassin's Creed Syndicate (and I'm pretty sure this makes it my first time being completely caught up on the series), and, well...

Now, right off the bat, I was thrown off by something strange: the presence of pre-rendered cutscenes. Assassin's Creed has always used these very sparingly, generally just at the very beginning or end of the game. Syndicate, however, uses pre-rendered cutscenes for the entire Templar storyline, only using in-engine cutscenes when the playable characters are on-screen, and probably only so their custom gear can be loaded in.
It took a long time for Jacob Frye to grow on me. Right off the bat, I preferred Evie, and I stuck with her through most of the game. Jacob had a deadpan way of delivering humor that made the heart grow fonder, though. But still, the two protagonists didn't feel all that creative or interesting, and all of the side characters (besides #Maxwell Roth) were absolutely bland and forgettable. With little thought, I can recall at least a handful of Unity characters that were at least well-written enough to be somewhat memorable, but Syndicate gave the characters so little... character. They're almost all either boring or annoying.

Speaking of Unity, that game's launch was a disaster. Faces were missing, players were clipping, frames were dropping, and every fan's face was sopping :(
However, I didn't play Unity until long after it had been patched, and boy, was it patched. The game was even more polished than the franchise's latest runaway hit, Black Flag. Syndicate, however, featured all of the bugs that Unity was criticized for, but due to their toned down presence, seemingly haven't been patched at all. I saw missing faces, I clipped numerous times, the free running was clumsy, missions could break, timed missions would open with long dialogue that I had no choice but to skip if I wanted to not fail the mission, I often simply wouldn't take fall damage if I went (strangely) flying off a building, throwing knives would frequently kill someone behind me instead of in front, quest characters have disappeared on me, and overall, the game is just a bit of a mess.
Unity also took a few steps to slightly change the franchise's repetitive combat: it wasn't a big change, no, I called it a slight one. I recall hearing some people complain about it being "too hard," but I thought Unity might've done Assassin's Creed combat best. Syndicate does it worst. Never has Assassin's Creed combat been more button-mashy and repetitive.
Unity also had a vast variety of customization, and that was actually pretty sick. Tops could be mixed with hoods could be mixed with pants and with boots, as well as a wide assortment of weaponry. Syndicate thought for some reason that the next big revolution for the franchise would be to strip away features, so Evie and Jacob have only a couple handful of set outfits between them, and a small assortment of colors to choose from. Besides that, there are only three melee weapon types: brass knuckles, cane sword, and kukri (knife). I swear, even Ezio had more customization variety than these two put together. "Tools" have also been cut back, with only two bomb types, throwing knives, the gun, and hallucination darts. No sleep darts, no coins, no distractions or other bomb types. Why have as many features as the other games when you can have less?

You do get to recruit members from your gang to accompany you on your journey, a la Saints Row, but unlike every other game that's done this, the gang cannot be customized. There is an upgrade tree to raise their skill, but you cannot modify your gang. You can't change their outfits or their style. This isn't really your gang.

I honestly don't think any aspect of this game was very well executed. The free running, the combat, the cutscenes, even just the city design and how it's to be incorporated with your free running was all poorly done. This world just doesn't feel like it was meant to climb and jump around in, it feels like it was made to zipline in. There are few free running "paths" like in previous games, to ease travel, and many of the paths that are present don't have the proper spacing between them to be usable, especially on the water.
Sometimes I'd try to jump down off a building just to hurry my way down, but the game wouldn't let me, because I'd take fall damage. Not because I'd die, just because I'd take some damage. I kept trying to lower myself, but I couldn't. I had to find a place where the game could slowly let me down with the "parkour down" mechanic (which worked much smoother in Unity: probably due to the presence of those "paths").
Unity comparison again: we've lost our wonderful interiors. Unity had very much of these (many of which also operated as part of these parkour paths, what do you know?), and Syndicate has very few. It's just one more detail that makes Syndicate feel like an afterthought.

There are so many little things that kept nagging at me, things that might not have bothered me as much if it weren't for there being so many shitty aspects of this game. The game had too many of those "pseudo cutscenes," the ones where the game doesn't change the lighting conditions or introduce any cinematic angles, but just uses basic animations and scripting to get the NPCs where they want them, and don't bother properly animating the lips. These wide-angle single-shot cutscenes are at the beginning and end, and often in the middle of most unimportant side missions, and I just fucking hated them. Some of these don't even change the angle at all, and are just seen from Frye's third-person camera, which, though it can be moved away, will quickly snap back to what it thinks you should be focusing on, and that pissed me off too.
The world lacks detail, the missions lack variety, and it just results in the worst Assassin's Creed game I've ever played. The game only offered one consistent source of enjoyment: The Dreadful Crimes DLC. That one's just fantastic, has an enjoyable story and gameplay, and gives a break from the mindless repetitiveness of the rest of the game. What a surprise that this comparatively small DLC blows the Jack the Ripper DLC out of the water, as that just offers more of the same bullshit. Another relatively enjoyable break from the rest of the game was an extensive World War I section, which actually features a mini campaign featuring Jacob Frye's granddaughter, Lydia Frye. This minor change in setting (still being set in a locked off part of London) can't fix the various gameplay issues, though, and the missions are as repetitive as the rest of the game.

This isn't a review, it's a rant. I've enjoyed every Assassin's Creed I've played before. Each game had its flaws, minor or major, but I've never looked at one as an utter failure before. Syndicate does nothing better than any of its counterparts, instead doing most things much worse. This game shouldn't have been made, and I shouldn't have wasted 50 hours of my time completing every single mission.