Happy Action Theater is an open-ended game, providing eighteen different modes that incorporate features of the Kinect motion-sensing and camera system. Players can select any one of the eighteen modes, or opt to have the game randomly select modes and cycle through them every few minutes. The game can support the tracking of up to 6 players.
Within most modes there are no goals, only to perform certain actions for the Kinect as to create humorous results in a form of augmented reality on the console's display. For example, one mode simulates a flow of lava that fills the player's room on the game's screen, and depicts the player within it. From here, the player can kick at rocks that float on the lava, interact with small animated flame sparks that jump around, or by "immersing" themselves in the lava, can have their hands temporarily shoot fireballs to "wipe out" other players on screen for a short period of time. Another mode simulates Space Invaders, with the players required to hold their hands up and move about as to destroy attacking forces on screen; while a score is kept, the mode is endless. The game does include a limited number of achievements for certain actions.
Source: Wikipedia, "Happy Action Theater", available under the CC-BY-SA License.