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

Do not allow your opponent to lead the game at any point with any team in a non-simulated game.

Like a contract

Assassinate Travis

Assassinate Layla

Approach the church

Eliminate the Saints

Defeat Sanchez with your bare hands

Buy an upgrade

Acquire the Silverballers

Assassinate Wade

Exit the mines

Enter the train in the train station