The character sprites for Sissy and Sassy are taken from the Dizzy
games by Codemasters
. First, the sprites were included for testing only, but as they fitted well in the game, the authors tried to get permission to use the sprite in the non-commercial game. As it was unclear who had the rights on the Dizzy character in 1996, they couldn't get this permission, but as the game was released in the public domain only without commercial interests, the developers used the sprites without permission.