Doom
  
Gameboy Advance

  


God Mode:

  During gameplay pause the game, then hold R and L and press A, A, B, A, A, A, 
  A, A.


All weapons, keys, Items:

  During gameplay pause the game, then hold R and L and press A, B, B, A, A, A, 
  A, A.
Level Skip:

  If you are totally stuck on a level, then use this cheat to skip it all together. 
  Pause the game, hold L + R and press A, B, A, A, B, B, B, and then A. The word 
  loading will appear if you got it right.


Invincibility:

  During gameplay pause the game, then hold R and L and press B, B, B, A, A, A, 
  A, A.


Computer Map:

  During gameplay pause the game, then hold R and L and press B, A, A, A, A, A, 
  A, A.


Berserk Mode:

  During gameplay pause the game, then hold R and L and press B, A, B, A, A, A, 
  A, A.


Radiation Suit:

  During gameplay pause the game, then hold R and L and press B, B, A, A, A, A, 
  A, A. 


  Thanks to Revolution readers Symbiode and Ben Alqadhi!