Perfect Kill
10Kill all enemies in Karnak in single player.
Unlocked: 02 Jan 2013 17:28:46
Complete Metropolis level in single player on serious difficulty without loading.
Unlocked: 02 Jan 2013 16:01:15
Serious Sam
30Complete the game in single player on serious difficulty.
Unlocked: 02 Jan 2013 14:41:05
Find at least 50 secrets in single player.
Unlocked: 02 Jan 2013 02:29:28
Complete the game in single player without firing a single bullet or shell.
Unlocked: 30 Dec 2012 17:51:43
Serious Run
15Complete the game in single player by beating estimated time on each level.
Unlocked: 30 Dec 2012 17:51:43
Pierce at least 10 enemies with a single cannonball.
Unlocked: 30 Dec 2012 16:19:44
Complete any level in single player.
Unlocked: 30 Dec 2012 14:21:18
Complete a co-op game on serious difficulty and extra enemy strength on 400%.
Unlocked: 29 Dec 2012 16:59:10
Game Master
20Complete the game.
Unlocked: 29 Dec 2012 16:59:09
Co-op Hippie
10Complete The Great Pyramid in co-op with blood option set to hippie.
Unlocked: 29 Dec 2012 14:01:52
Complete any level in co-op.
Unlocked: 29 Dec 2012 14:01:51