While playing, bring up the console with CTRL and ~. Then type any of the following codes:

Cheat Code - Effect

/Scrap.SetMoney # - Add # Money.
/Scrap.SetSaveVar [number] - Set lives.
/evil - You can't dead.
/free - Noclip Mode.
/freeze - Everyone don't move (except you)
/go - Unpause game.
/god - Can\'t be dead.
/killer - Unlimited energy.
/megagod - Ultra fast weapons.
/speed # - Change Time Speed in World.
/stop - Pause game.
/unfreeze - Disable freeze.
/yoda - Enemies die when close to you.