Missions themselves are more tactical, and the new combat and exploration controls are an important part of this. You can finally crouch manually (hold the L trigger) and lock into cover with a tap of the A button. If you're spotted by a guard you'll see an outline of your last known position on screen, better informing you of where you might be slipping up but also giving you the opportunity to deliberately gain their attention before sneaking away and flanking your attackers. The R trigger is still your command for parkouring up and over objects and buildings, but the addition of the A (for up) and B (for down) buttons mean you can better inform the game exactly where you want to go. There are fewer slip ups, and less accidental jumps off 200ft towers into a sprawling, desynchronised heap on the ground.
Combat has been made a little harder - at any rate, enemies feel like they have more health, but the parry button is still there and the reintroduction of health packs allows you to still stand and batter someone for quite some time until they finally, finally submit and die. The best that can probably be said about Unity's combat is that it has finally become more attractive to avoid it - due to how unfun and slow actual combat can be compared to stealthy, quick kills that let you move on undetected, but also due to the new enhancements in stealth bonuses that you can now acquire.
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