I only managed to pass the first level. :) The idea is interesting, and the graphs and animations are nice. The grumpy smiths are pretty brutal—they punish the apprentice for a single mistake!
Maybe in a game like this, you need enemies with more or less fixed routes with some variations. Otherwise, when it is completely random like now (it looks random at least), you can’t really plan your job. Also, it just may happen that one smith makes a puddle, and the other one discovers it soon after, and you don’t even have a chance to clean up because you can approach the place without approaching these bullies.
Overall, it’s an excellent idea, and it could make a nice, puzzle-like game when tuned a little.