I'm currently replaying Assassin's Creed 3, and that game was the worst Assassin's Creed game to date until I just started playing it again. It was, in my opinion, a mediocre game bordering on poor. Once I finish the game and it sticks to being as good as it is now, it definitely puts the AC series as a good bunch of games nearly through and through with one outlier (Unity is still below average to me [the first AC is also not great I believe, though the story is fine]). Originally AC3 was a huge bore for me, the visual hitches were a hindrance and the story and characters were underwhelming; all those things are not so true anymore, I liked Black Flag and I also liked Rogue for their on foot gameplay (which I also played relatively recently), and three is basically the same type of thing, though with a few differences.
Some things that bothered me was always running away from enemies after not being incognito due to killing British soldiers, and the combat was frustrating. The one thing I did like about that was the stellar soundtrack that played, which was the one thing I loved about the game minus the fact it doesn't really play when you explore, but even that is negligible now. The combat isn't frustrating, it looks cool and is just fun. Getting around the city when guards are on alert, it's almost akin to old-style MGS (without the vision cones) as you go through ally's waiting for soldiers to pass. I don't remember ever using the town criers either which would have alleviated that issue. I borrowed the game from my brother when it came out, that's the last time I played the game.
I have the feeling I was being quite hasty with it all and it, in turn, made me lack the know how to really play the game well which led to it being a lot more frustrating than it could have been and it clouded my view of the game overall. On the story side of it, I felt Connor was a boring, kind of whiny character, especially coming off of Ezio, and yet now I see him as a sympathetic character that strives for good and equality in harsh times for groups of people. He's not as romantic and sarcastic as Ezio, but in his own way, he is respectable as a character I'm finding. I also think the game does a better job with the setting than I remember, be it through visual as you walk the cities, or how people are treated in the world depicted in the story. Playing the game on Xbox One through backward compatibility has made the frame rate not quite as bad as it was. There are still hitches, but it's not as bothersome.
I haven't run into anything noteworthy in terms of glitches, the worst is just the pop in which has occurred in all AC games. The sound design even by today's standards is phenomenal. I love the Lorne Balfe soundtrack, and the voice work is exceptional as well with decent sounds of the city life. The only issue is sometimes a lack of sound, like when there's a crowd and you can't hear them, which kind of tarnishes the atmosphere in the moment. I also wish there was some music during the time you roam the environments, but it's not as much an issue now as I said. What game was similar for you?