Mew’s Addition to the Game Happened Because of a Prank
In an Ask Iwata interview before the release of Pokemon HeartGold and SoulSilver, the Director of Game Freak Shigeki Morimoto, and the CEO and President of the Pokemon Company Tsunekazu Ishihara, admitted that the reason behind all of the Mew glitches present in the first generation games was because of a prank.
According to the interview, before the games were released, they took out a debug feature which freed 300 bytes of space which they decided to use on adding Mew.
It’s a good thing that they did, because if they didn’t, Mew might never have been available. As Morimoto noted “But then due to an unforeseen bug, Mew ended up appearing in some players’ games. It looked like we planned all of this, but that wasn’t the case. So although it caused all sorts of problems to many concerned, fortunately enough it ended up having a positive effect.”
