How is the game being funded?

The Metropolis Project is based on the idea of community funding, otherwise known as "bounty funding" or an assurance contract.  To understand how it works,consider how a game is usually funded: A game studio comes up with an idea for a game and raises money to produce it, usually with the help of a publisher.  When the game is released, the publisher (or other backer) then receives a portion of the proceeds from sales;  Any proceeds beyond the cost of the game become profits for the studio and the publisher.  At first glance then, it appears that the game is funded by the publisher;  But really, the publisher is only disbursing money temporarily, in exchange for a portion of the eventual sales.  It is actually these sales, the individual purchases from fans, that fund the game.
 
With Metropolis we are, fundamentally, financing the game from the same source (the end user);  But with community funding, we reverse the usual paradigm.  Rather than first making a game and selling it, we intend to gather financing from individual community members.  This is done through pledges: members will pledge to donate a certain amount, and when the total budget for the game has been pledged, the pledges will be called in and development will begin.  Since the game will have already been paid for at this point, it will be released for free, along with its source code, when development is finished.