Concept
Collaborative control gameplay (as it stands) refers to the game type that allows many users - or players in this case - to control a single entity in a game. Although the term "collaborative control gameplay" is not commonly used to describe this concept, I find it is a very fitting and succinct title.
To define this concept it is important to first differentiate it from a common multiplayer, or massively multiplayer gameplay. The difference being that in a conventional multiplayer game, each player has at least one entity that only they control. When a player controls a single entity, this entity is generally called an avatar. The manner or methods of control is irrelevant for our definition, as long as it is only one player making the control decisions for the entity. Of course the actions of other players may have a direct impact on a player's avatar, they may even induce involuntary changes; however, if the ultimate gameplay decisions are being made by only one player, the game is not collaboratively controlled.
A collaboatively controlled gameplay requires that there be multiple players controlling a single entity. Thus a group of players must work simealtaneously and in concert in order to achieve the intended goals. This idea has been implemented in various forms (consider even the 3-legged-race) and has been applied in many venues. For example, the Interactive Dance Club created by Ryan Ulyate and David Bianciardi allowed for a myriad of users to interactively and simultaneously create sounds and imagery through the motions of their bodies and the manipulation of various inputs. The users of the club were collaboratively controlling a shared musical experience.
A large audience (100 persons or more) participating in an electronic game is an interesting context. Because of the number of people in an audience, a shared interactive experience will almost always have to be collaboratively controlled. Probablly the first implementation of a collaborative control system at this large scale is Cinematrix Interactive Entertainment Systems ® created by Rachel and Loren Carpenter and presented at SIGGRAPH in 1991. This system utilized panels with opposing red and green sides that audience members held in front of them to cast a red or green vote as input. There has been surprisingly few other implementations of this concept since it's presentation over 17 years ago. The best example of research that has been done specifically on collaborative control for large audiences is the work of Dan Maynes-Aminzade, Randy Pausch, and Steve Seitz. Together they implemented three different methods of inputs for collaborative control gameplay and then compiled the results and lessons learned from their trials. The three implemetned methods allowed audience members to give gameplay input by (1) leaning left and right, (2) batting a beach ball into the air and using it's shadow as a tracking point, and (3) pointing a laser pointer dot at the projected game screen.
The method for gameplay input in a collaboratively controlled game is an important consideration. Consider that there are two possibilities for player proximity. Players may be isolated and interacting remotely via the internet or other network or players may be together in a single room and collectively interacting with a single game system or computer. In the former case the actions of each player must be transmited to every other player, ideally in real time. This can be problematic and limiting. If there is any lag in system or network performance the delay is liable to confuse the players' ability to collaborate. Alternatively, players working together in a single room provides a number of advantages including simple and instant verbal communication. Player's can also generally see - depending on the input method - what others are giving as input to the game and align themselves with those decisions. In this context we might expect players to exhibit a type of flocking behavoir where action leaders (either conciously or subconciously) begin to emerge.