Platinum- Collect all trophies in Killzone. Captain- Complete all levels on easy difficulty. Colonel- Complete all levels on normal difficulty. General- Complete all levels on hard difficulty. Toothpick Master- Get 20 kills with the M32 combat knife. Backstabber- Get 20 kills with the FSK-7 Fury. Bullheaded- Get 20 headshots with the M4 Semi-Automatic Pistol.