Kinect Party's minigames can track up to six players at once. Players work together to pop balloons, shoot down enemies, and more. Some minigames work better with less people, as standing in front of each other can cause players to disappear. The game is definitely intended to be played with others though.
Kinect Party is the sequel to Happy Action Theater. It more than doubles the number of minigames from the first title and supports local co-op for up to 6 players.