I got through the puzzle ok, but am confused on the ending. I arrive at the farm, but their's no mice or seed and using the shovel and watering can on the dirt does not trigger anything?
Ah, I'm sorry about the confusion. It's not very clear, but you need to solve all the previous locations for them to arrive at the house. In other words, you need to get a blue spiral symbol instead of a red X at all locations except the rightmost one on the map. Then, the seed and the creatures will appear at the house.
I believe you have the lake left to solve? A hint is that the "shovel" is supposed to be an oar.