Ms. Pac-Man started its life as an unauthorized modification of Pac-Man by General Computer Corporation called Crazy Otto.  Around the time GCC was creating Crazy Otto they were being sued by Atari over Super Missile Attack, an unauthorized modification they had made of Atari’s game Missile Command.  GCC lost that case, and decided to try selling Crazy Otto to Midway, the company which had distributed Pac-Man in North America, rather than risking another lawsuit.  Midway had been waiting impatiently for Namco to produce a sequel to Pac-Man, and they jumped on the chance to buy Crazy Otto.  They modified the character sprites to make them look more Pac-Man-esque, making the main character female as a tribute to the female fans who helped make Pac-Man so popular.

The gameplay of Ms. Pac-Man is essentially the same as Pac-Man.  The main differences are that the level color and layout change every other level, and the fruit bounce around the maze rather than remaining stationary.

Ms. Pac-Man was released in North America by Midway in 1981.

Pac-Man is one of the most popular games of all time.  Gameplay is very simple: the player controls Pac-Man, moving him around a maze eating dots while being chased by four ghosts: Blinky (red), Pinky (pink), Inky (light blue), and Clyde (orange).  Each level has four larger dots which when eaten turn all the ghosts blue, making them temporarily vulnerable to being eaten by Pac-Man.  When a level is cleared of all its dots the level ends and the next level begins.

The game’s creator, Toru Iwatani, has said that the shape of Pac-Man was inspired by a pizza with a missing slice.  The game was released by Namco in Japan, and distributed in North America by Midway.