Go to "Options," then Cheats."
All the Cheats:
Cheat code : Result
iopred : Cute message
DayDream : Cute message
John Rambo : Unlocks Bow&Arrow
Old Faithful : Unlocks ChainGun (Found by Austinator)
Its a Jackal : Unlocks SniperRifle (Found by deathcharms)
This is my boomstick : Unlocks DoubleShotgun (Found by Patware)
Shrapnel : Unlocks FlakCannon (Found by Patware)
Follow the leader : Unlocks GuidedLauncher (Found by razer)
Moonshine : Unlocks DrunkenLauncher (Found by Dukeofme)
Gloop : Unlocks GooGun (Found by Sky-Fighter Ace)
9 Volt : Unlocks SparkPlug (Found by 24/7 Gamer)
Australians all let us rejoice : Unlocks Bladerang (Found by Shellman)
Alpha : Unlocks LaserRifle (Found by mastervb)
Beta : Unlocks AutoLaserRifle (Found by Ghundio)
Gamma : Unlocks LaserShotgun (Found by mastervb)
I dont have time to bleed : Unlocks Anytime (Found by ravenfrost)
Call in artillery : Unlocks Airstrike (Found by zell96740)
Missile launch detected : Unlocks ABombLauncher (Found by ravenfrost)
Bass in your face : Unlocks Soundwaave (Found by Patware)
Wash away the rain : Unlocks BlackHoleGenerator (Found by deathcharms)
Ive got jungle fever, shes got jungle fever : Unlocks Amazon Jungle (Found by iforgot2314)
Aint no mountain high enough : Unlocks Canyon Lands (Found by Patware)
Who rides the wrecking ball : Unlocks Underground Lab (Found by ndrd)
up up down down left right left right b a select start : Unlocks All Weapons (Found by deathcharms and bobbler)
You are the moon master : Unlocks All Levels
Collectors Edition Cheats:
Firelines : Unlocks FireMines
Pure Pwnage : Unlocks AntiMatterCannon