We previewed this sandbox survival game in April last year, but even we were surprised when Linden Labs revealed that it had simply ceased development and removed it from Steam.
The reason behind this decision is explained on the Patterns community page.
we are working on an ambitious project to create the next-generation virtual world, while we continue to improve Second Life and grow Blocksworld.
Those who purchased the game will still have it in their Steam library, but it is no longer for sale. Also, all online capabilities will no longer function.