As pointed out by VG247, Ubisoft had previously made Watch Dogs free in November, and now it looks like the game will be free to play again, at least while this offer is still valid. That being said, these aren’t necessarily the latest titles from Ubisoft and to a certain extent, some of them might even be considered “old”.
However if you never got around to playing them due to whatever reasons you might have, then now might be a good time to check them out since it won’t cost you a dime, although you will have to download Uplay and download the games through Ubisoft’s platform in order to qualify for it.
The deal will run until the December 23 and ends at 10am UTC, so if you’d like to learn more, you can hit up Ubisoft’s page for the details.