Before settling on Pac-Man's family, the friends Pac-Man rescued in Pac-Man World were going to be characters from other 1980s Namco games:

• Dig Dug (also known as Taizo Hori) from Dig Dug, who Chomp-Chomp took the place of. A remnant of this choice can be seen in the opening cutscene where Chomp-Chomp is kidnapped by being dragged underground, where Dig Dug's gameplay takes place.
• Valkyrie and Whirlo from the Valkyrie series, who were replaced with Pac-Baby and Pooka. There is also a thematic remnant of this choice in Pac-Baby and Pooka's kidnapping, where they are anchored into the sky, as Valkyrie lives in the heavens.
• Mappy from Mappy, who was replaced by Jr. Pac-Man.

Gil from The Tower of Druaga and Miru from Pac & Pal were also intended to appear, while Professor Pac-Man and Ms. Pac-Man were part of the original concept and remained.

It was ultimately decided to focus on Pac-Man characters instead of crossover characters, but when it was discovered that there weren't enough "pac-people" to make rescuable for each world, Pooka from Dig Dug was added to fill out the cast, being the same spherical shape as Pac-Man's family and a favorite of the development team. It is unknown why Miru, who was already a Pac-Man character, went unused.

Pac-Man World's ending has been noted for containing darker humor compared to the game's otherwise lighthearted tone. The game's antagonist Toc-Man, the robot impostor who kidnapped Pac-Man's family, is revealed to be Orson, a tearful grey ghost who just wanted to be as famous as Pac-Man, who responds to this by pretending to show sympathy before eating him. According to the game's designer, Scott Rogers, his reasoning for this tonal shift was:


Rogers also noted that they wanted to have Pac-Man respond to Orson's cry of "nobody loves a ghost!" with "I do!" (in the sense of loving to eat a ghost), but this was scrapped alongside Pac-Man's voice as a whole.

Pac-Man World: Re-Pac amends this divisive ending by designating it as a bad ending and adding a new good ending. If the player fails to rescue Pac-Man's family, the ending plays out as it did in the original game, with an added scene where Orson's ghost minions choose to rescue Pac-Man's family themselves, but if the player successfully rescues Pac-Man's family, he opts to forgive Orson.

In preview builds of Pac-Man World, H.M.S. Windbag was called "H.M.S. Hanky". The name was changed due to South Park starting around the game's development, and the developers of Pac-Man World wanting to avoid association with the character of Mr. Hankey the Christmas Poo.

In an interview with Scott Rogers, a designer of Pac-World, he revealed that Toc-Man's name was a nod to "Namcot," a short-lived Namco division created to handle console game releases.