Bill (blue guy) is modeled after Arnold Schwarzenegger in Predator (1987) and Lance (red guy) is modeled after Sylvester Stallone in Rambo: First Blood Part II (1985).
Was one of the few games where the home port is more popular than the arcade version.
The name Contra was chosen as the American title because symbols on the side of the Japanese arcade cabinet formed the sound "Kon Tra" when spoken aloud.
In the UK and other countries the human characters are changed to robots in the late Probotector (1990).
The front cover of the game shares a resemblance to Predator (Bill Rizer's stance), Rambo 2 (Lance Bean's stance) and the Alien movies.