Contra: The Alien Wars Cheats

Contra: The Alien Wars Level 4 in Easy Mode
Normally the easy game ends on level 3, but with this code you can access level 4. To do so, enter the password 21LN. Unfortunately, the game will end after Level 4.

Contra: The Alien Wars Level Skip
Enter the password "H2F2". While playing, press Start to advance to the next level.

Contra: The Alien Wars Passwords

Level  Password2      3KNT3      MDWH4      2S3W5      1Z5C