Currently, we are working on the public alpha of the open source part of the game. It will be the first public binary release, a version you can download and try out without compiling from source yourself. It will include the game itself, some demo levels and the level editor. There are still some things to sort out, though. (Currently, we are struggling with some quirks in fullscreen mode on Windows 7.) But we hope, it won't take too long. So stay tuned.