If you took the images of the most well know characters in the game and started asking people who they were most people would have difficulty naming more than one or two characters, and the best you could hope for is a handful of people who could tell you the names of the games these characters came from; in contrast, I suspect the vast majority of people would be able to identify most of Mario, Luigi, Pricess Peach, Bowser, Yoshi, Donkey Kong, Link, Princess Zelda, Kirby, Starfox, Pikichu, and Sonic with quite a few being able to identify Wario, Diddy Kong, Gannon, Samus, and Solid Snake from Super Smash Bros. Brawl.
Ultimately, the difference is that Nintendo has sold (something like) half a billion copies of games including characters from the Mushroom kingdom, (something like) 200 million copies of games including characters from Pokemon, (something like) 100 million copies of games including characters from the Zelda universe, and most of the other characters came from games in series that have spawned multiple decades with tens of millions in sales; and many of these characters have had decades worth in merchandising and appearances outside of videogames (with a few having dedicated television shows). Sony's characters come from franchises that mostly didn't exist in 2005, have sales that are tiny in comparison to most of Nintendo's series, and have never made any impact outside of their games.