It is for the DS.
Mario, Luigi, Wario, Waluigi, DK, Diddy, Toad and Toadette are going on vacation with Peach. They soon arrive in Dinosaur Land. Mario and friends start chatting with some Yoshis and Peach dissapears. They all go to find her.
Morton Jr. (C2)
Ice Quadruplets (T3)
Same as in SMW.
You can play a 3D version of Mario Bros. as a minigame. There are two versions. Coin Collection and Baddie Battle. It is 8 player like the story.