Note: To use these codes simply enter
then in the console ('~' key toggles console)

Cheat Codes:

playbetter - god mode on/off
twoweeks - powerup on/off
meatwagon - kill all non-boss monsters
victor - kill all monsters (including BOSS)

Other Codes:
 
angermonsters - monsters get angry
crazymonsters - monsters out for blood
kiwi - clipping on/off
showcoords - show coordinates
weapprev - select previous weapon
weapnext - select next weapon

Item Spawn Code: (this is my favorite and most used code)
spawn  - create an item where  is one of the
following item names:

item_weapon_firewall
item_weapon_maceballs
item_weapon_magicmissile
item_weapon_phoenixbow
item_weapon_redrain_bow
item_weapon_sphereofannihilation
 
item_defense_meteorbarrier
item_defense_polymorph
item_defense_powerup
item_defense_ringofrepulsion
item_defense_shield
item_defense_teleport

item_health_full
item_health_half

item_mana_combo_half
item_mana_combo_quarter
item_mana_defensive_full
item_mana_defensive_half
item_mana_offensive_full
item_mana_offensive_half

item_puzzle_canyonkey
item_puzzle_cloudkey
item_puzzle_cog
item_puzzle_crystal
item_puzzle_dungeonkey
item_puzzle_highpriestesskey
item_puzzle_highpriestesssymbol
item_puzzle_hive2amulet
item_puzzle_hive2gem
item_puzzle_hive2spear
item_puzzle_minecartwheel
item_puzzle_ore
item_puzzle_plazacontainer
item_puzzle_potion
item_puzzle_refinedore
item_puzzle_shield
item_puzzle_slumcontainer
item_puzzle_tavernkey
item_puzzle_tome
item_puzzle_townkey