I like the direction, and much like the lower comments, feel like it could use some extra features (Time scaling, various upgrades, etc) to make for a more satisfying game loop. For the time you had and the effort it takes though, this is lovely, and I'm especially impressed that you made NPC code, since that is magic to me atm. Overall, neat premise and very cute execution!
Sidenote, I seem to have trouble gaining money overtime? Might mean I need to let it run longer tho.