Complete the game in single player on serious difficulty.
Complete the game in single player without firing a single bullet or shell.
Complete Metropolis level in single player on serious difficulty without loading.
Complete a co-op game on serious difficulty and extra enemy strength on 400%.
Kill all enemies in Karnak in single player.
Find at least 50 secrets in single player.
Complete the game in single player by beating estimated time on each level.
Complete the game.
Complete The Great Pyramid in co-op with blood option set to hippie.
Pierce at least 10 enemies with a single cannonball.
Complete any level in co-op.
Complete any level in single player.
