"Ubisoft has announced it's extending its Happy Playdays giveaway and adding Watch Dogs to the selection of PC games available for free for a limited time."
http://ca.ign.com/articles/2017/12/18/ubisoft-giving-away-two-free-games-for-pc-this-holiday
The Ubisoft site:
https://www.ubisoft.com/en-gb/event/happy-playdays-2017/#207315645
Didn't they just give away all of these recently?