According to the newest issue of Famitsu in which Masahiro Sakurai discusses internal development quips for the Super Smash Bros. series, it was originally Shigeru Miyamoto’s idea to see Pac-Man in the brawler. Sakurai says Miyamoto came to him and asked him about Pac-Man as a guest character, but at the time Sakurai felt that it was too far-fetched as Pac-Man hadn’t been given a 3D form outside of advertising.
During development of Smash Bros. Brawl, Mr. Shigeru Miyamoto of Nintendo approached me and asked, ‘Can’t we have Pac-Man as a guest character?’ At the time, imagining the image of Pac-Man and his incomplete pizza shape, I thought to myself, ‘Hmmm… That’s a little too farfetched.
While Pac-Man is a new addition for Super Smash Bros. on the Wii U and the Nintendo 3DS, he almost made his debut in Brawl.