At menu screen enter the following cheats: 

sunnycheats - Activate Access To Cheats 
open all - Access All Levels 

During gameplay enter the following cheats: 

gun - Activate Laser 
magnet - Activate Magnet 
water - Activate Water Ball 
fire - Activate Fire Ball 
acid - Activate Acid Ball 
rocket - Rocket Launcher 
flash - Thunderbolt 
ufo - Summon Ufo 
two - Ball Doubler 
four - Four Ball 
gotonext - Next Level 
addlife - Extra Life