http://store.steampowered.com/app/2500/?snr=1_4_4__13
It was/is part of the "Humble Frozenbyte Bundle" which you could/can pay whatever you want for it, depending on if it's still going or not.
I just feel like I might be the only person in the room not getting a joke or something.
Edit: Still going for...10 days or so longer. http://www.humblebundle.com/