This game is incredible. Hacking as a puzzle-solving mechanic has made this one of my favourite games ever made. It's extremely refreshing to see how many clever ways Ubisoft has used hacking to enrich a puzzle in the open world.
QR Codes - Each QR code in the open world is painted on different surfaces, sometimes even on different buildings. You have to think critically and approach the QR code at an angle that makes it appear like the disjointed QR code is one unbroken surface. When you hack the camera that provides that necessary angle, you have solved the puzzle.
Privacy Invasions / Weapons Investigation / ctOS towers: With these puzzles you usually need to activate your phone's profiler and follow communication/electrical lines from a locked door or locked console to a linked, hackable console. It's fun following the lines across streets, across multiple houses, using hackable lifts to gain good vantage points, bouncing between hacked cameras until you can get a good view of the hackable console.
ctOS breaches: These are basically timed versions of the Privacy Invasion / ctOS tower puzzles, except you don't follow communication/electrical lines, you just run from console to console and use cameras or lifts to get the right vantage points to complete each ctOS hack.
Criminal Convoys / Fixer Contracts / Open World Automobile Travel in general: It's a blast to succeed a car chase after lining up a blown steam pipe with a pursuer's car, or using traffic lights to cause a car crash.
Stealth and hacking: Stealth in Assassin's Creed games is usually uninspired. Here there are a dozen ways to tackle each stealth situation. Hack an earpiece to jam communications, or use a consumable Jam Comms item instead. Hack stationary cameras or an enemy's head-mounted camera to get a view of the situation, etc...
