I had a lot of fun with the demo, but I also encountered a game-breaking bug. Eventually, two enemy units (an archer and a villager) spawned on the same space and only the archer moved and planned an attack, while the villager just stood there endlessly. The game remained in the enemy's turn phase, preventing me from continuing to play, though the interface otherwise remained responsive.
I also encountered a non-gamebreaking bug, namely that sickness does not spread to enemy units as advertised, at least if you have the Exhume on Sickness Kill effect.