Contra 4 Hints & Cheats

Enter the Konami code in the pause menu to either upgrade your weapons fully or kill your character. It can only be used in Normal or Hard mode (easy gives you full upgrades automatically)

It's still the same Konami Code, except that A and B are replaced with B and Y, respectively. Input at the start screen of the original Contra game, then press start to begin the game with 30 lives.

At the title screen for Super C enter the following code

To access Sound Mode in the unlockable Super C, as the game's logo is fading in on the title screen hold Y+B and press Start.

Complete the game on any difficulty to unlock Challenge Mode. This includes Easy.

Same as the real classic Contra in NES, once you beat the game, you'll start over with hard mode. More enemies, more bullets flying around.

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.