You don't always have to buy the game individually. It is often included in the following libraries:
Released by Ubisoft, Watch Dogs is an open-world action-adventure game that introduced players to Aiden Pearce, a brilliant hacker and former thug. Set in a fictionalized version of Chicago, the game centers on the "ctOS" (Central Operating System), which controls the city's infrastructure. Players use Aiden’s smartphone to hack into traffic lights, security cameras, and bank accounts to exact revenge for a family tragedy. watch-dogs-1-game-link
If you are looking for the "link" to play the game, it is available across all major digital storefronts. Buying through official channels ensures you get the latest patches, DLC support, and a secure download. You don't always have to buy the game individually
Subscribers get access to the "Complete Edition" including the Bad Blood DLC. Players use Aiden’s smartphone to hack into traffic