Up front, is it good?
Actually, yes. It has a lot going for it.
Is it great?
LOL, no. There is a plethora of issues with the game. Some due to horrible QA on Ubisoft's part. Some due to their massively overreaching. And many due to neglect. But when the game hits on all cylinders, it's a beautiful thing.
Disclaimer: I have not yet finished the story. So I'll not give an opinion on it. I'm almost there, but without seeing it to the end, it would be more speculation than opinion. Having said that, it's nowhere near what I was hoping for. The French Revolution and Reign of Terror are HUGE moments in history. And in this game, they serve as little more than set dressing. For a series that has tried to do historical fiction, but let you feel as if you're living a part of history, this one doesn't do so well. Perhaps this was a conscious decision on their part since everyone complained that Connor "Forrest Gumped" his way through the American Revolution. I understand their wanting to avoid that again. But you could have thrown us a few bones.
(And what little history we see feels... wrong. Or too simplistic maybe)
Arno as the main character = Ezio lite. Not horrible, but not nearly as charismatic as Ezio or Edward, nor as outright badass as Altair, Ezio or Edward. But hey, he's a vast improvement over Connor at least.
Graphics: Gorgeous... when it's not frame dipping. That said, despite numerous complaints about said bad frame rate, it's at its worst in the tutorial missions when you first play as Arno. Once you're out on your own living the life of an assassin, it's not as noticeable.
But that doesn't excuse the bugs: falling through the world. Getting stuck inside walls. NPCs materializing right in front of you (or especially LOL worthy, dropping out of the sky). Clunky animations, or textures not loading correctly. The latter seems to have improved, if not disappeared altogether.
Game play (mechanics): A few new things that are fun , and some removal of others that make me wonder why they took them out. Like picking up a weapon, or whistle or grabbing/throwing people. Combat is a bit more of a challenge. You're not going to pull 20,30, or even 50 guards and just roll through them. If you're good, you can handle 5-6, maybe a bit more. But it'll be a challenge or you'll have to cheat. For most people, pulling more than 4-5 will equal death. (and that's assuming you have appropriate gear)
Free running is both better and god awfully frustrating sometimes. Parkouring up and down is nice. Going through windows is wildly inconsistent though.
Stealth... sucks. It's awful. They committed a mortal sin here. Their cover system is the clunkiest, horribly executed piece of trash I've ever seen. Disguises are useless. Guards will see you THROUGH a building, or won't see you standing right in front of him. Hitman 2 had a better stealth system, and that was 2 generations ago! HELL, Watchdogs had a better stealth system, and Ubisoft made it!
The game is way too bloated. The map of Paris is ENORMOUS. I think if you took all of the cities from AC2, combined them with Rome from Brotherhood, and add Havana, Kingston and Nassau all into one map, you'd have Paris. That might be an exaggeration, but that's how it feels. And the map is overflowing with side stuff to do. Too much to do really. Well, having a lot to do is good. But some of it is pointless or boring.
Co-op missions are a BLAST. Some people complain that grouping with randoms = just wild combat with zero stealth and a race to the end. They're right. But it's FUN. It's also equally fun grouping with people who actually communicate and do things more stealthily (or as much as the game lets you anyway).
NO TAILING / EAVESDROP missions!!!! Plus 100 points.
Customizing is good and works decently.
Some of the new animation for kills, both assassination type kills and finishing moves are brutal. The camera could use some work when fighting in a room, or against a larger group.
Bottom line: The game is wildly ambitious, but fails to stick the landing. Still better than AC3 in almost every way. I'll be interested to see how they take this more or less raw version of an upgraded AC, and improve, polish and tighten it for the next outing.
It's worth playing. But it's a middle of the pack AC game at best.