Xbox 360 Crackdown

Developed by Realtime Worlds
Available on Xbox 360

Crackdown is a third-person shooter set in a sandbox environment, akin to
Mercenaries: Playground of Destruction. After selecting one of the
predefined Agent characters, the player is assigned to defeat the Kingpin of
each gang, though there is no precise approach to do this, leaving players to
select their preferred method.