Full list of all 55 Watch_Dogs 2 achievements worth 1,260 gamerscore. It takes around 40-50 hours to unlock all of the achievements in the base game.
The base game contains 49 achievements worth 1,000 Gamerscore, and there are 4 DLC packs containing 6 achievements worth 260 Gamerscore.
Neutralize 1 Hunter in Bounty Hunter mode
Successfully neutralize 5 fugitives in Bounty Hunter
Do a 140 meters long jump while driving a vehicle
Do a sailboat race
Trigger the hack of the century
Complete 5 DedSec Events
Successfully complete an online Co-op Operation
Finish Operation: Robot Wars
Finish Operation: Shanghaied
Finish Operation: Hack teh World
Finish Operation: Ubistolen
Finish Operation: W4tched
Ride a cable car
Finish Operation: Eye for An Eye
Finish Operation: $911
Travel 200 meters on top of a car by hacking it
Hijack a boat
Use the "Call the cops" hack on the donut-disguised man in Haight-Ashbury
Drive one of the Unique Vehicles
Take a picture of someone vomiting
Finish Operation: Hacker War
Drive 4 km in the world while driving the Merengue from Elek Motors
Take 25 ScoutX location pictures
Buy the Gatorfeet Whine Country footwear
Pet 10 dogs
Get photobombed in a selfie
Finish Operation: Shadow
Do a drone race
Escape a Level 5 felony
Do a stealth takedown on 30 enemies
Get all the eKart upgrades
Finish Operation: Limp Nudle
Buy a shirt in the Nudle vending machine
Finish Operation: Haum Sweet Haum
Finish Operation: False Profits
Hijack a bus
Buy a two handed weapon at the 3D printer
Hack a robot
Buy all the apps in the App Shop
Finish Operation: Cyber Driver
Successfully invade another hacker
Do a bike race
Make 3 jumps in a row aboard a vehicle
Buy some pants after the party
Erase your past identity in the Blume servers
Collect all the Key Data hidden in the world
Buy 25 cars in car dealerships
Finish Operation: Looking Glass
Finish Operation: Power to the Sheeple
Finish Operation: Off the Hook
Finish Operation: Caustic Progress
Finish Operation: Bad Medicine
Finish Operation: Automata
Reach the maximum win streak bonus in Showd0wn
Finish Operation: Moscow Gambit