I wonder what kind of animal Pac-Man is. Is he a decapitated jaundiced human head? Or an amoeba mutated to giant size? Or maybe a decapitated jaundiced shark head?
The answer to this question is none of the above. Pac-Man is clearly a space alien who is visiting the uninhabited planet of Neverendingmazes. He's tripping on acid, and that's why he thinks he's always being chased by ghosts. They represent the mistakes he's made in his pre-alienstronaut days, when he was a hired killer for the alien mafia. As for what the pretzels and apples represent, I'll leave that to the historians to decide.
The acid is laced with pot, hence the rampant munchies.
Ms. Pac-Man, meanwhile, is Pac-Man's lost soulmate, who also became an acid-addicted alienstronaut who also happened to visit Neverendingmazes. (They used to sit next to each other in alien math class at the Pac-People School for the Academically Gifted but Unlucky in the Ways of Love, and neither ever mustered up the courage to ask the other out). As fortune would have it, she landed on a different part of the planet. The part with better graphics and more cleverly designed mazes.
They will never meet one another again, trapped in their own private hells of panic-tinged solitude.