The Steam versions for Windows and Mac have just been released!
http://store.steampowered.com/app/287900/
If you are a backer of these versions (or Linux) you will be sent a Steam Key later today. If you haven't received a Steam Key by the end of the week please let us know.
The Linux version will be added to Steam in due course. As will additional viewing angles for all versions.
On behalf of the whole team, thanks once again for your support!
Ade.