I'm impressed how well the payment curve works! Very fun and well made, even more impressive that it's built literally from raw javascript as far as I can tell. Thanks for open sourcing it so others can learn from the code!
One thing I found myself wishing I could do was view applicants and then buy an appropriate house the for the applicant before denying them. I think I understand the gameplay reason why that wouldn't be allowed, but based on the existing UX it felt like something I could have done.