Rebel Cops

This is obtained by completing the tutorial mission. The first half you will be guided through so you can't make a mistake at this point. After the halfway point you'll have to complete the mission by yourself. It's not a very hard level, just ensure that any cops that go down are healed up before taking out the last of the enemies. If you turn on Infinite Saves this becomes a lot easier, as you can save before making any moves and reload if it goes wrong.