I've encountered a couple of bugs, but it's certainly one of the more stable games I've played. Steam reckons I've spent about 400 hours in it, but that includes the times I've left it minimised while I'm doing other stuff, but probably still a good 250 hours or so of actual playing. That includes the alpha and beta releases, though!
Surprised how much mileage I've got out of it since I felt actually quite sceptical about the idea when I first backed it, but I'll be surprised if it has any serious competition for my personal game of the year.
