Trivia: The scenes from the amusment park in the movie were filmed at Playland, in Rye, NY.
Trivia: The big piano scene was actually rehearsed months before shooting. Tom and Robert had to practise on a cardboard cut out with exact dimensions of the real piano. On the day of shooting there were stunt doubles instead of them to film their feet. But once the director saw that they could do it, the stunt doubles were never used.
Answer: According to imdb: Though some believe it to be Colossal (Cave) Adventure or an early Sierra Game, no known game up to 1988 accepts the commands "melt ice wizard" or "throw thermal pod" (as used in the movie), therefore one can assume the game screen was simply created for the movie.
Carl Missouri