By: 

   Release date: 



   The codes.

   Load  the game as usual and don't do anything until the high score screen
 appears.  Type COMMANDER and then press the fire button. After a few moments
 press  F10.  If your ship flickers you are now invulnerable, and have infinite
 expansions and smart bombs.

 F1-F5         Other six levels of the expansion.
 F8            Move ahead a level.
 F10           Toggle cheat mode.