User blog comment:MarkvA/Gamescom - Assassin's Creed III Preview/@comment-3202167-20120816114503/@comment-5216016-20120816135155

Expansions that last longer than most of actual new 60$ games nowadays. Besides, AC2 can be beaten in 6 hours or less if you will do the main story only.

Oh, and you know what? AC games keep track how long you played them. Here are my times:

AC2 - 18h  ACB - 21h    ACR - 17h

Doesn't seem all that shorter too me. (DLC included minus TLA because that's not in the main game and doesn't add to the time)