Mario Hoops 3-on-3 (Mario Basket 3on3 in Japan and Mario Slam Basketball in Europe) is a basketball game developed by Square Enix for the Nintendo DS and first completely unveiled at the E3 showcase.
In the beginning, it was meant to be an original game, but Square Enix felt that it would work well with the Mario label. Square Enix contacted Nintendo, and Nintendo allowed them to use it. There is also a follow-up called Mario Sports Mix which was released on the Wii in 2011.
The game features many characters from the Mario universe both old and new.