Game modifiers:
Unlock the following Game Modifiers by completing Campaign mode on the corresponding difficulties:
GAME MODIFIER – HOW TO UNLOCK
Double-Physics (Doubles force of explosions) – Complete Campaign on Medium difficulty.
Hollywood Mode (Enemies have big heads) – Complete Campaign on Easy difficulty.
Tough Guys (Enemies have more health) – Complete Campaign on Hard difficulty.Achievements:ACHIEVEMENT – HOW TO UNLOCKColor Me Impressed (10 points) – Complete a mission on Normal without dying, failing, restarting, or continuing campaign. Droppin Bombs (5 points) – Call in the airstrike to defeat the Command Center. Hummer (10 points) – Kill 15 enemies on the HMV turret. Kaboom (5 points) – Destroy the gas station. Long Range (10 points) – Kill 20 enemies with a sniper rifle. One Hundo (50 points) – Unlock all the unlockables. Pool and Dive (5 points) – Survive the pool attack. Private (15 points) – Complete the game on Easy Difficulty. Rocketman (10 points) – Kill 2 aliens with one Rocket. Seen Your Video (5 points) – Watch an unlocked video. Sergeant Major (50 points) – Complete the game on Hard Difficulty. Staff Sergeant (25 points) – Complete the game on Normal Difficulty.?