Acquire all trophies.
Achieve Bronze in all challenges.
Complete the story on "Easy" difficulty.
Complete 4th Millennium on story
Complete Mesozoic Era on story
Complete 4th Century BC on story
Complete 6th Millennium on story
Played all modes
Achieve Silver in all challenges.
Complete the story on "Normal" difficulty.
Take no damage for an entire level in the story mode.
Shoot 250,000 bullets.
Get 500 Headshots.
Survive 25 waves in Arcade
Kill 1000 Zombies.
Kill 1000 Skelton Army.
Kill 1000 Robots.
Kill 1000 Dinosaurs.
Achieve Gold in all challenges.
Complete the story on "Hard" difficulty.
Unlock all the weapons.
Unlock all the perks.