To see it in action, head on over to gameinformer.com and watch the trailer that was uploaded yesterday afternoon.

Will this mini-game, called "Balloon Trip Breeze," also contain a multi-player mode? The folks at Game Informer don't seem to know, unfortunately. Personally, I hope it does--despite the fact that it's likely I'll be playing Nintendo Land (and practically every other Wii U game I purchase) all by myself.
See also: 'Welp, it seems I'll be buying a 3DS XL a bit sooner than I initially thought I would'