While playing, press the Tilde key, right under ESC and type in the 
cheat like so, CHEAT *cheatcode* 
*If you use cheat codes, you will not enter to the high scores table* 

ALLOFF - All cheat codes is disabled 
MOREENERGYON - Now every destroyed space ship gives you 50 energy. 
MOREENERGYOFF - Now every destroyed spaceship gives you 1/10 of its 
energy. 
NEXTWEAPON - Next weapon level. 
PREVIOUSWEAPON - Previous weapon level. 
MAXWEAPON - Maximum weapon level (15). 
NOANTIBONUSON - Anti bonuses is disabled. 
NOANTIBONUSOFF - Anti bonuses is enabled. 
SUPERSHIELDON - Now you have super shield. 
SUPERSHIELDOFF - Now you have normal shield. 
SUPERATTACKON - Now all weapons have the super strength. 
SUPERATTACKOFF - Now all your weapons have the normal strength.