Would this be a CYOP? [url]http://www.kongregate.com/forums/7099-forum-games/topics/447013-the-path-of-exile-prime-cyop-rpg-cyop-open-to-all[/url] and [url]http://www.kongregate.com/forums/7099-forum-games/topics/404037-parasite-quest-cyop[/url]
Like: you present us with a situation, and we squabble and vote over what we do? Those are fun, and can get very silly and out of hand, but those don't need a limit of how many people join in. 
For those not interested in clicking through links:
The Chose Your Own Path/Adventure is a lot like what this would be, numerous players (often with competing agendas) controlling a single entity, and voting on the best path to follow, with the GM posting the responses.
The one's I pulled were my personal favorites, though many of them are simply slice of life, and don't deal with being a god/xenomorph
I'm not sure if this is what you have in mind, though this is what I thought of when you mentioned this concept.