Those users who are running AMD CPU/GPU configurations have been having problems with Assassin's Creed: Unity on PC and Ubisoft have now responded to say that they are aware of the problem.
They have posted on the official Ubisoft forums to state that the problem isn't widespread and that it is down to AMD configurations.
We are aware that the graphics performance of Assassin’s Creed Unity on PC may be adversely affected by certain AMD CPU and GPU configurations.
This should not affect the vast majority of PC players, but rest assured that AMD and Ubisoft are continuing to work together closely to resolve the issue, and will provide more information as soon as it is available.
The Steam forums are full of reviews stating that the game runs poorly, crashes a lot, has audio issues and more.
Ubisoft recently removed all of their games from the Steam store in the US and UK as well, and now they are having some serious issues. Whoops.