There are some more details pertaining to Nintendo Land below coming from Game Informer:
- there will be single player only games
- Donkey Kong and Balloon Fight attractions feature single player
- these two games also support off-TV play
- random “games” or activities that you can play outside of the big theme parks
Does this mean that some of the attractions won’t have multiplayer? I think the random “games” are the activities where you earn Nintendo memorabilia.