Contra 4 Cheats :
99 lives glitch
This glitch will allow you to obtain 99 lives. In order for this to work, you must have zero lives left, and die at the same time you get an extra life. The best way to do this is by killing the mini boss of level 1 because that usually gets you an extra life. Get hit by one of the fireballs it drops down on you the instant you destroy it.