Tried it at a convention two days ago. It was the full game. We tried Piranha Plant Slide, Music Park and another one I forgot.
The controls and items were fine (only seen one blue shell) and the level designs were good (although I wanted Piranha Plant Slide to have less sewers and more retro overworld).
My only complaint is that for some reason the 3D gave me a headache even though I only played 3 races, other games did that to me as well but after a while of playing and it wasn't as severe. I'm not sure whether it's because of the game or that the device wasn't steady.
I wanted to try the first person mode but the guy there didn't know how to use it and I was too busy winning to try
Also the amount of hate for Waluigi is unbelievable, even Metal Mario and Queen Bee don't get as much hate.