In Smash, there’s this thing called “clone characters”. 
The 14 basic and 5 hidden characters make up the foundation, and on the character selection screen’s edges there are the character’s variations that appear next to the characters’ slots.
During development, we thought it wouldn’t be possible to make more than about 16 characters however hard we tried.
Having said that, the customers would want to have even more…
There, we prepared characters that shared Special Moves and motions (movement) with some of the other characters in order to save programming and motion creation time, but while looking and feeling different.
This is just like Luigi to Mario in the previous game.
Actually, even making the character models to secure their slot is not easy, and I know that it would make me, the person who adjusts character parameters the most (like attack power and jumps), busier than it would anyone else.
That said, if the options are “do” or “don’t”, then I thought it was definitely better to “do”, so I put them in the game.
(That’s because even if these are cut, there will be no characters added)
Based on Pikachu, we prepared Pichu.
When you actually play [the game] and observe, you will find Pichu and Pikachu to be very different.
In this Smash, the honour of being the weakest is bestowed to Pichu.
Compared to Jigglypuff, who was technically the weakest character last time but was quite potent in the right hands, Pichu has the physical weakness of shocking itself and taking damage when performing attacks that involve electricity.
Its weight is the lightest among all characters too, and overall its attacks are not powerful, either.
To put it the other way, if you can win with this character, you’ll look really cool.
If you see some brave warrior using this character in high level tournament matches, please applaud for them.
Clear Event 37: Legendary Pokémon.
Alternatively, play 200 multiplayer matches.
You probably have noticed it already, but you can unlock all characters by just racking up the number of matches played.
It’s simple, so we made it a little tiring,  but we’ve made it so that people who don’t play anything but versus matches can unlock all of the characters just fine.
(These images were taken during development)
 A more proper translation for clone characters would be “model swap characters”. The term “clone” was never officially used in Smash.
 The original text used, “しんどくしています”, took me quite a while to translate. Turns out that it comes from “しんどい“, which in Kansai dialect means “tired”.