Contra 4
Pause the game and press Up(2), Down(2), Left, Right, Left, Right, B, A, Start to fully upgrade all your weapons. Note: This code can only be entered once per level, as repeating it will cause death. Also, you must have an upgradeable weapon to avoid the death effect. This code does not work on the Easy difficulty setting.
Lose a life exactly when you gain an extra life to have 99 lives. A good way to do this is by killing the mini-Boss in Level 1 because you usually get an extra life. Get hit by one of the fireballs it shoots the instant you destroy it.
Successfully complete the game to unlock Challenge mode.
Successfully complete the indicated number of challenges to unlock the corresponding bonus:
- NES Contra: 4
- NES Super C: 8
- Probotector character: 12
- Nobuya Nakazato interview: 16
- Lucia character: 20
- Contra 3 comic: 24
- Sheena Etranzi: 28
- Jimbo and Sully from Contra 3: The Alien Wars: 36
- Sound Test option: 40
- NES Super C: 8
Successfully complete the game. At the character selection screen, press Up or Down to choose an alternate color.
Successfully complete the game on the Normal or Hard difficulty setting to view an alternate ending.
Before the demonstration begins at the Contra title screen, press Up(2), Down(2), Left, Right, Left, Right, Y, B, Start.
Successfully complete the game to begin a new game in Hard mode.
At the Super C title screen, press Right, Left, Down, Up, B, Y.
As the game's logo is fading at the Super C title screen, hold Y + B and press Start.