We have startet a crowdfunding on IndieGoGo that offers the early access version of Imagine Earth for $25 and the final version for $15. Additionally there are a lot of other perks that will put your name into the credits, give you the chance to name a city and more.
The first 100 supporters will earn a special badge for the Imagine Earth forums and will stand out in an extra section of the game credits as "Space Pioneers"!