A day after getting the game i beat the main story line, and it was a good game. Assassin's guild has every assassin at max rank to, not much left to do beside find the flags and buy the rest of the properties, along with trying to get full synchronization on most missions.
Multiplayer? After you finish everything in single player, that's really the only thing that's left. Alternatively, move on to Revelations if you can afford it. Constantinople is so much more fun to explore than Rome.
It's definitely the best game in the series, but Rome doesn't even hold a matchstick to Constantinople.
I disliked Constantinople, seemed kind of generic. Rome had diversity, ruins, the Coliseum, fields, cities, Vatican, Saint Angelo. Constantinople had Hagia Sofia, and nothing really outstanding.
Eh, it must be my fascination with Middle Eastern architecture that that makes me like it. It's just so different from what I've seen firsthand.
Right now, what i've got is fully leveled assassino guild, All treasures, All feathers, Armor of Brutus, 1 shop quest left, 71/72 - 101 flags.
I started doing all the miscellaneous objectives after the main story, so of course it took little time, although some missions are a B**** to do. I have every single borgia flag, all romulus lairs done, all treasure chests, all feathers, Started on the guild challenges, aside from the Assassino guild, cause that's done, and i may make an account for Uplay so i can have some different available costumes. Edit: All shop quest's Done