YOU NEED AN INTERNET CONNECTION TO PLAY. EVERY TIME YOU WANT TO PLAY.
Just the above should be enough for everyone to boycott Ubisoft and any game that uses this pig-headed method of copy protection, which DOES NOT WORK to protect anything. The Mac version was available online cracked within a few weeks of its release.
You can avoid the internet connection requirement by using a little program called AC 2 Cracked Launcher (Mac), to be found on the internet. This is not illegal if you have already bought the game.
HOWEVER, this game is just not worth playing on the Mac, because of lack of gamepad support> even external USB keyboard/mouse support is buggy.
This Mac version is a frigging joke.
NO XBOX360 controller support. I have tried everything, including Gamepad Companion which works on everything else... The game seem to have some buggy USB drivers.
CRAP EXTERNAL USB KEYBOARD SUPPORT and USB mouse support : both flakey, connection often drops and you have to quit and re-launch the game . The game seems unable to let you use both the laptop keyboard and an external keyboard at the same time.
Which is irrelevant anyway, as THIS GAME IS NOT PLAYABLE with a mouse and keyboard. If you go ahead and buy this, when you get to the part when you have to chase some thief through the city you will remember these words.
The interface and controls are terrible , very hard to get used to, too many buttons, no visual feedback on which actual key to press for the multitude of actions you can perform.
This Mac version is just buggy and hastily put together to sell.
The game blows in so many ways... cut scenes that cannot be skipped, with out-of-sync voices, dialogues that cannot be exited... Another case of "great graphics, but I can't be bothered with this..."