In European areas, the first few games were renamed as "Probotector" for the console ports, with the players and human looking enemies turned into robots, and "Gryzor" for the computer ports. This is because the BPJM or Bundesprüfstelle für jugendgefährdende Medien (Federal Department for Media Harmful to Young Persons) had a law that prohibited the sale and/or advertisement of media deemed too violent to children, including "content which glorifies war". This lasted until Contra: Legacy of War, which was when they started to use the Contra name from then on.
Contributed by gamemaster1991