So I've read the kickstarter. They want to support more platforms as they get more money, with Linux being their #2 priority, and other platforms as they get even more money.
They're using the Unity Engine, which has the ability to generate code for basically every platform EXCEPT Linux. It should be almost trivial for them to make their game and then port it to a huge number of platforms (iOS, Android, Mac, Wii, XBLA, etc...) except Linux. It would be very difficult to port the game to Linux after it has already been written for the Unity engine, almost having to rewrite the entire thing using a different engine. This is what I keep talking about: if you have a goal in mind and choose a library that runs directly contrary to that goal you're going to have a bad time.