Never Get Shot/die,never Lose A Credit, Keep Special Guns
In this cheat you will never get shot/die, never lose a credit and keep special guns (except. Shocker, freeze gun, flamethrower, etc.
up (x2) down (x2) left, right, left, right b, b
p.s. I found this cheat by messing up on a different cheat.
(CheatCode Note: This is untested and may not work.)