In the Japanese version, Mutant League Football is a well-known series. This is Mutant League Hockey♪ I think it was only released overseas. The package design is similar to Football, so those who like it will love it☆ I believe a Mega Key was not required, but it might be better for those who have an environment where they can play overseas Mega Drive games. Case and instruction manual are damaged. *Please note that it will be sold as is. #MutantLeagueHockey #MutantLeagueFootball #MegaDrive #OverseasGameSoftware #GENESIS