During play press 'F9' five times to activate the cheat mode. Now use the following keys:
'F1'--Add to power up | 'F5'-----Invincibility
'F2'--Add to power up | 'F6'--Special weapon 1
'F3'-------Add energy | 'F7'--Special weapon 2
'F4'------Fill energy | 'F8'--Special Weapon 3
'DEL'------------Die!