So cool! I loved the old-school art style, it remembers me of old RPG games. I don't know if it is a problem with my browser, but I was able to place tiles outside the frame of the game window. But since I didn't download it I can't say for sure if it is a bug or not.
We developed a similar game, in which you have to create a road but with a different concept and art style.
Amazin job and good luck with the jam!