Check out Opus Magnum dev Zachtronics' entire game design history for free

Here's something neat! You can now grab SpaceChem and Opus Magnum developer Zachtronics' complete game design history without spending a dime. 

The studio has made the digital version of 'Zach-Like,' a book of comprehensive behind-the-scenes game design documents (like the one below), available for free through Steam. 

Breaking the news on Twitter, the developer revealed the digital version of the book contains the full contents of the physical release, along with breakdowns of its pre-SpaceChem titles and a bunch of playable weird prototypes and early builds.

The tome is well worth a read if you're even vaguely interested in the art of game design and development, or if you just want to fiddle around with the early versions of Zachtronics' games, some of which have never been released.

Right now, the book-launcher and games are all Windows-only, so Mac users will need to procure a PC to have a gander.