Yoshiki Watabe, producer of "", thought of the idea and approached series creator Yuji Horii and together they brainstormed the games genre and style. Previously the two had discussed making a game for children while working on a port of "Dragon Warrior" to the Game Boy, and the need for a main character appealing to children. When first conceived, the game had the blue slime protagonist wielding a sword and shield, and a gameplay test was done in this style, but was rejected because developers felt "This isn't really a slime game, this is like a blue Link". Developers then started over and asked what a slime could do that a normal character couldn't, from which the idea of the player stretching and launching the slime at enemies and objects came from. The developers also chose to keep humans out of the game, due to that if they did appear, they would probably just run around killing all the Slimes.