To unlock alternate sound effects, at the main menu, press UP(2), DOWN(2), LEFT, RIGHT, LEFT, RIGHT, B, A
ACHIEVEMENT - HOW TO UNLOCK Bravery (15 points) - Use only your knife to beat the Harbor Level. Fair Fight (10 points) - Reach the mortar without defeating any unarmed soldier in Missile Base. Good Start (10 points) - Beat the Missile Base. Knife Master (20 points) - Beat all levels using only your knife and no powerups. Mad Marine (30 points) - Rescue the POWs twice. Not Bad (10 points) - Get a score of 50,000 or more. Reflexes (15 points) - Beat the Missile Base without dying. Stamina (15 points) - Beat the Bridge Level. Stealth (15 points) - Beat Missile Base, deafting less than 18 enemies. Teamwork (20 points) - Score 200,000 or more playing an Xbox Live co-op match. True Marine (20 points) - Rescue the POWs in less than 10 minutes. Victory (20 points) - Beat the Enemy Prison Camp.