The Nintendo rep let me and the kid I was playing pick the controller we wanted to use the Gamepad or the Wii remote. I let the kid pick the Gamepad so I was stuck using the Wii remote.
Anyway the demo started with the character select screen were the playable characters were Mario, Luigi, Peach, Yoshi, Donkey Kong, Bowser, Toad, Koopa, Daisy, Toadette, Wario and Waluigi. The kid picked Yoshi and I picked Waluigi. After that the new Mario Circuit intro played with the Mario Kart 7 music. I start out the race with a normal start but, soon after I Gladed off of Mario Circuit near the end of the first lap. The anti gravity kicked in the second lap and it looked very good. I was in 6th place near the end of the race, it looked like the kid had the race in the bag however, in the final item box I got a golden mushroom and the kid got hit but a few red shells dropping him to 4th place. Wasting no time I used the golden mushroom and won the race. The kid almost made a comeback with three mushrooms but, he could not match the speed of the golden mushroom. The items I saw were the golden mushroom, triple mushrooms, mushroom, banana, triple bananas, fire flower, green shell, triple green shells red shell, triple red shells star, thunderbolt, blooper and bomb-omb. I asked the nintendo rep about the characters and controllers, he said all of the controllers will be useable in the full game and that there will be more characters. I also saw a few Shy Guy signs so he is likely returning as a playable character. Sadly I was able to play Mario Circuit so I still don't not much about Mario Kart 8.