Cheat Mode...
	Hidden level...
	Steam Achievements...

While in gameplay press ~ key to activate the console. Type "cht_bEnableCheats=1" (without the quotes) to enable the first set of cheats options such as Max Health, All Guns, Level Selection, kill all enemies. After entering this command press ~ then ESC and then F1 you should now have the cheat menu. From now on at the bottom of the menu (Load,Save Options,Leaderboards...) you should be able to see Cheats F3, this is the cheats menu. Type "cht_bEnableCheats=2" (without the quotes) to enable second set of cheats options God Mode, Ghost, Invisible and Fly mode. After entering this command press ~ then ESC and then F1 you should now have the cheat menu. From now on at the bottom of the menu (Load,Save Options,Leaderboards...) you should be able to see Cheats F3, this is the cheats menu.

Code	Effect
cht_bEnableCheats=2	God Mode, Ghost, Invisible and Fly mode
cht_bEnableCheats=1	Max Health, All Guns, Level Selection, Kill all enemies

In the 'Valley of the Kings' level, destroy all the statues.

Achievement	How to unlock
1337 Fragger	Frag a total of 1337 players.
Backstabber	Frag 100 players with a knife from behind.
Butcher	Frag 100 players with a knife.
Cannon Expert	Pierce at least 10 enemies with a single cannonball.
Co-op Beginner	Complete any level in co-op.
Co-op Hippy	Complete The Great Pyramid in co-op with blood option set to hippy.
Crazy Fragger	Frag a total of 500 players.
Deathmatch Champion	Win 1000 deathmatch games.
Deathmatch Duelist	Win 25 1-on-1 deathmatches.
Deathmatch Marathon	Complete a deathmatch with frag limit set to at least 200. Frag limit must be reached!
Deathmatch Marathon Winner	Win a deathmatch marathon.
Deathmatch Master	Win 100 deathmatch games.
Deathmatch Veteran	Complete 100 deathmatches.
Desperate Fragger	Frag 25 players with a knife while having no more than 10 health left.
Diverse Fragger	Frag 100 different players in deathmatch.
Frag Combo	Perform 4 frags with each being no more than 10 seconds apart from the previous frag in at least 4 player deathmatch.
Fragger	Frag a total of 100 players.
Game Master	Complete the game.
Grudge	Frag the same player 5 times in a row in at least 4 player deathmatch.
I am invincible	Complete the game in single player without firing a single bullet or shell.
Look Ma, I won!	Win a deathmatch.
Look, it's a secret	Find at least 50 secrets in single player.
Metropolis King	Complete Metropolis level in single player on serious difficulty without loading.
Nemesis	Frag the same player 10 times during a single round in at least 4 player deathmatch.
Perfect Kill	Kill all enemies in Karnak in single player.
Rocket Jumper	Perform 100 rocket jumps.
Royal Frag Combo	Frag all players in a single frag combo.
Serious Beginner	Complete any level in single player.
Serious Co-op	Complete a co-op game on serious difficulty and extra enemy strength on 400%.
Serious Fragger	Frag a total of 1000 players.
Serious Run	Complete the game in single player by beating estimated time on each level.
Serious Sam	Complete the game in single player on serious difficulty.
Swimming Instructor	Drown an enemy.
Swordsman	Frag 100 players in a knife-to-knife fight.
Untouchable	Win an at least 4 player deathmatch by reaching frag limit of at least 25 without dying.