Sister Sonic

[gamemaster1991]

Popful Mail is a pretty popular game. So popular, that it stopped the developers from making it apart of the Sonic the Hedgehog series. You see, when the Sega CD version was being developed, there was a plan by Sega Falcom (a Sega and Nihon Falcom team-up) to pull a Doki Doki Panic on the game to have it more marketable in America (and possible other places). The idea was to take all of the characters in the game and reskin them to Sonic characters and make the main character a long lost sister to Sonic and rename the game "Sister Sonic."

I'm not sure how far the redesign got, but I know it was not far. When fans of the PC original caught wind of this, they sent many angry letters. With so many angry fan letters being sent in, the project was canceled. A normal, Not-Sonic version was later relesed.
 Victor Ireland
Interview with Victor Ireland