Use a knife to remove a bullet

Commandeer the enemy space station. (Complete "Loki" on any difficulty.)

Defeat 20 enemies by shooting from the hip (without aiming with L1/R1)

Defeat 30 enemies with the M9

Upgrade any Magic to the next level

Win the Buttonless MiniGame against a Manticore

Ride the snake back to the Tower of Delphi

Solve the Rolling Crusher Puzzle

Spill 500 buckets of blood on Kratos

Defeat Megaera and the Titan Hecatonchires

Complete the MP Training in Olympus

Defeat the infected Hand of Aegaeon