The Crackdown franchise is based around kills for skills agent and has players taking control of genetically enhanced super cops to save the city. This is generally the plot of the games as the Crackdown agent tackles gang bosses and brings stability. You collect Agility Orbs among doing other tasks for skill points and this is a big part of the series. The first game has you saving Pacific City from the gangs, the second has you tackling a super mutant outbreak which was odd. In the third game you once again aim to save the city from gangs in a full destructible world with more fun and a large scale than ever before.