Coming out today is the full build for Windows and Mac OS X, but sadly not Linux. However, our former intern Eric Griffith pointed out that a Linux port is planned according to one of the developers in a comment he made last month.
The comment by one of the Red Hook Studio developers reads, "Linux support is still planned, but it won't be till post launch. We know of players using WINE to get it to run currently. We know how much you all want it, and we also know how chill linux users are, but we will get it out there for you all eventually." While the Linux support is not out there today, apparently it does work with Wine should you be after a new dungeon game.
More details on the game via Steam. The launch price is $20 USD.