Unlock the following Achievement titles by performing the corresponding tasks:
Bomber - Use 50 grenades. Executioner - Get 200 head shots. Game Cleared (Easy) - Beat all chapters on Easy. Game Cleared (Hard) - Beat all chapters on Hard. Game Cleared (Normal) - Beat all chapters on Normal. Head Hunter - Get 100 head shots. Head Shooter - Get 50 head shots. Hunter Killer - Kill 100 Hunters. Licker Killer - Kill 50 Lickers. Put Trust In Others - Have your partner kill 30 enemies. S.T.A.R.S. Mission - Beat the secret mission. Trigger Happy - Fire more than 10,000 rounds. Ultra-Rich - Collect 150,000 coins. Wealthy - Collect 100,000 coins. Well-Off - Collect 50,000 coins. Zombie Hunter - Kill 500 zombies. Zombie Killer - Kill 1,000 zombies. Zombie Shooter - Kill 100 zombies.