Upgrade Weapons:
In the pause menu enter the Konami code(Up, Up, Down, Down, Left, Right Left, Right, B, A, Start)to upgrade your weapons. This code can only be used once per life and only in Normal or Hard mode.
Challenge Mode Unlockables:
Unlock Challenge Mode by beating the game on any difficulty, than you can unlock extra games.
| Contra (NES) | Beat 4 challenges in Challenge Mode |
| Probotector | Beat 12 challenges in Challenge Mode |
| Sheena Etranzi | Beat 28 challenges in Challenge Mode |
| Super C (NES) | Beat 8 challenges in Challenge Mode |
30 Lives in Original Contra:
To begin the game with 30 lives enter Up, Up, Down, Down, Left, Right Left, Right, Y, B at the title screen.
10 Lives in Super C:
At the title screen for Super C enter Right, Left, Down, Up, B, Y for 10 Extra Men.
Hard mode for Classic Contra:
Beat the game and you'll start over with hard mode.
Super C Sound Test:
In Super C as the game's logo is fading in on the title screen hold Y+B and press Start.
99 lives glitch:
In order for this to work, you must have zero lives left, and die at the same time you get an extra life. A good way to do this is by killing the mini boss of level 1 because it usually gets you an extra life.