Crackdown (3) on the Controls
This one is seriously the first thing that needs to be addressed. The controls for the original Crackdown games were functional, but they still had major issues.
The shooting was the biggest offender. It went with the standard third-person shooter controls, but also allowed you to target limbs of whoever you happened to be aiming at. You had a better chance hitting someone with spray and pray than you did aiming down the sights. The lock-on would rather make romance eyes at the car while some jagoff four floors up with a rocket launcher turns you into a hacky sack. Ideally, Crackdown 3 will just ditch the lock-on and limb targeting in favor of the one every other shooter uses; just aim down sights and shoot however you want.
Oh, and one last thing, improve the climbing system that led to so many accidental deaths in the previous two games. Infamous and Assassin’s Creed are two games Crackdown can take inspiration from. Either is preferable to trying to reach a building and bouncing off, only to fall all the way down.