Demo is pretty fun. The game feels a bit short lived though, but it is an early alpha. Hopefully more features will be added that extend the basic system. Another basic resource or two, tons of different items to craft, reasons to craft, and large scale projects would add a lot of value to the system. There just doesn't seem to be much of a purpose beyond the design part; at least gnomoria has a survival aspect to keep the player involved beyond construction.
Still, I've only played the demo. Contributed and emailed this morning, waiting on my key. Funding goal was reached today, so they are probably behind on sending them out.