Cheat Codes: During gameplay just press ~ to open the game console give in one of the next commands:

Code - Effect
BeMyMonkey() - Toggle Cheat Mode
God() - Toggle God Mode
Invisible() - Toggle Invisibility
Loaded() - Get all weapons
AllAmmo() - Give player ammo for all weapons
GodEx(X) - Toggle God Mode for the given actor
Phoenix() - Toggle Phoenix Powersuit
FearMe() - Enemy now fears you
Ghost() - Ghost Mode
Fly() - Fly Mode
Amphibious() - Underwater mode
Walk() - Normal, walking mode
SloMo(#) - Game Slomotion
SetJumpZ(#) - Set jump height
ToggleInfiniteAmmo() - Toggle Infinite Ammo
ToggleReloads() - Toggle Reloads
ToggleInvisibility() - Toggle Invisibility
Teleport() - Teleport to the spot the player is looking at
NextLevel() - Skip to next level
Open(x) - Open Map x
ToggleSpeed() - Double speed
SetSpeed(#) - Set player speed
ChangeSize(#) - Change Players Size
TogglePawnInvulnerability(P) - Toggle god mode on given pawn
Goodies(#, #) - Summon an array of goodies
Sum(x) - Summon Item X
Actors() - Full actor list
GotoActor(Name) - Change Location to the given Actor
Damage(#, Target) - Damage given target by the specified amount
DamageNPCs(#) - Damage NPC's by the given amount
SetHealth(#, Target) - Set health to the given amount for target
SetMyHealth(#) - Set player health to the given amount
HurtMe(#) - Hurt the player by the specified amount
ManCannon(#) - Gives all visible pawns damage
ToggleServos() - Toggle Animation Servos
ShowTeams() - Show player teams
Difficulty(#) - Change game difficulty
CheatView(x) - See what actor x's view is
ViewSelf() - Target Camera on player
ToggleTimeDemo() - Enable time demo
ToggleScoreBoard() - Toggle Score board
EnableFreeOrders(0/1) - Toggle Free Orders
BehindView() - Toggle Behind View
SetParticleDensity(#) - Set Particle Density
ToggleImpacts() - Toggle Impacts
SetWeaponTick(0/1) - Toggle Weapon tick code
SetWeaponFire(0/1) - Toggle Weapon firing
ToggleShowAll() - Show all hidden actors
ToggleShowKPs() - Show all keypoints
ToggleShowNPs() - Show all nagivation points
ToggleRMode() - Toggle RMode
SetEyeHeigth() - Set player eye height
KillActor(x) - Kill actor X
KillHitActor() - Kill actor under crosshair
KillHitNPC() - Kill NPC under crosshair
KillActiveNPCS() - Kill all active NPCS
KillDormantnPCS() - Kill all dormant NPCS
GibAllNPCS() - Gib all NPCs
GibHitNPC() - Gib the NPC under the crosshair
PO() - Toggle players only
ToggleFreezeView() - Toggle Freeze View
ToggleHUD() - Toggle HUD
SetCameraDist(#) - Set camera distance
FreeCamera(0/1) - Toggle free camera movement
SetFogR(#) - Set fog color Red
SetFogG(#) - Set fog color Green
SetFogB(#) - Set fog color Blue
SetFlash(#) -
ShowViewLine() -
SetFOV(#) -
ToggleFOV(#) -