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.
Avoid being Shot:
If you duck while standing in water, you will disappear below the surface and won't get hurt by gun shots or enemies running over you. This can also be used in the classic Contra.
Challenge Mode Unlockables:
Ulnock Challenge Mode by beating the game on any difficulty than
you can unlock extra games.
||How to Unlock
||Beat 4 challenges in Challenge Mode
||Beat 12 challenges in Challenge Mode
||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.
Thanks to Revolution Reader Boringman54!