Eliminate the Saints

Assassinate facility leaders

Exit the mines

Acquire the Silverballers

Execute a point shooting with 3 kills

Assassinate Wade's men

Enter the train in the train station

Achieve your first accident kill

Remain undetected in a whole checkpoint

Unlock a technique

Hide a body

Blend in successfully

In TranZit, kill one of the denizens of the forest while it is latched onto you.