I was playing this the other day on my tablet and thought it would be good if you could keep the weapon power-ups you had accumulated after dying.
Achieving this was actually quite simple since Galoob had already done a bunch of Genie codes to always begin with a specific power-up, so I just dissected one of those codes as a base and then tailored it to what I wanted. So anyway, the following codes will let you keep the exact shot-power you last had before biting the dust
GAME GENIE
HEVA-AYZG
HEVA-AYZN
RAW
0022A6:4A39
0022AC:4A39