CBS Electronics had a contest with this game. You had to find the secret word HELIOS (which is the Greek word for 'sun'), then send in an entry form to enter. The word was 'your key to exciting new surprises from CBS Electronics'. Each letter was given after completing a round. It’s unknown what happened with this contest.
Present in the PAL ROM is this strange line: (SENRCOM)
Screenshots (6)
Solar Fox — screenshot 1Solar Fox — screenshot 2Solar Fox — screenshot 3Solar Fox — screenshot 4Solar Fox — screenshot 5Solar Fox — screenshot 6