Most people wouldn't know this, but the game had a team of 2 guys make the games
One source states, "In it's earliest stages, Smash Bros. was essentially the after-work hobby project of Masahiro Sakurai (the creator of the Kirby series) and Soturu Iwata. Yes, that Iwata — the guy who's now Nintendo's banana contemplating president.
Keep staring buddy — maybe the answer to "What will make the Wii U sell?" is in there somewhere.
Sakurai would design the game after work, then send his ideas to Iwata who programmed the game himself. Slowly but surely over the span of many months, a primitive version of Smash Bros. began to come together"(Birch).