Cash Invaders

Cash Invaders cheat codes: 
Go to the options screen and choose cheat codes. Then enter one
of these codes (case insensitive):

endless supply     - endless ammo for any power-up you buy
triggerhappy       - more firepower, fast autofire for every weapon
bullseye           - display accuracy
credit check       - powerups cost nothing
starfleet          - start with 99 ships
jump to level  - start on level , example "jump to level 50"
target practice    - practise bonus rounds
sitting duck       - all enemies are snipers, extra hard mode
back to the roots  - Space Invaders style, stick to one level
keep the change    - no cash, invaders don't drop coins
big fat cheater    - all cheats at once