Nice game! The art style is super cute (I liked the shepherd gnome with the little goat). I had a hard time at first because, being a developer, I didn't read the manual, so I didn't understand buildings have to be next to each other. I think that could be easier to understand if you somehow highlighted the tiles that are next to other buildings... but that might make the game too easy.
Dragging cards was super smooth, I always have a hard time implementing mouse input! Can I ask wether the cards and the little area where the cards are are controls or node2d? I'm curious.
Anyway, I had fun! Good luck!