This game has hidden developer credits.
Professor Pac-Man swaps out the ghosts-and-dots maze antics in favor of quizzing youngsters. Unsurprisingly, it failed to catch on, and in fact many of the machines were sent back to Bally Midway to be converted into Pac-Land machines. Only 100 machines are known to still exist today.
Three different versions were planned for different audiences and areas: "Family", "Public", and "Prizes" (for normal arcades, bars, and casinos, respectively). However, the only version known to exist (also the only one known to have been produced) is the Family one.
Present in pp9 at 0x1F89:
PROFESSOR PAC-MAN COPYRIGHT DNA ALL RIGHTS RESERVED