Serious Co-op
Complete a co-op game on serious difficulty and extra enemy strength on 400%.
35 
Serious Sam
Complete the game in single player on serious difficulty.
30 
Look, It's a Secret
Find at least 50 secrets in single player.
30 
Game Master
Complete the game.
20 
Metropolis King
Complete Metropolis level in single player on serious difficulty without loading.
20 
Serious Run
Complete the game in single player by beating estimated time on each level.
15 
Serious Beginner
Complete any level in single player.
10 
I am Invincible
Complete the game in single player without firing a single bullet or shell.
10 
Perfect Kill
Kill all enemies in Karnak in single player.
10 
Co-op Hippie
Complete The Great Pyramid in co-op with blood option set to hippie.
10 
Cannon Expert
Pierce at least 10 enemies with a single cannonball.
5 
Co-op Beginner
Complete any level in co-op.
5