Thanks so much for all the detailed feedback! This will absolutely be helpful, as we are planning to take this game to a full release :D
After you capture the cat, you can go back to the cellar for the final boss! Unfortunately there is a bug that prevents the event from triggering that causes the cat to lead you to that fight. Also the dialogue for the mom is indeed bugged, sadly. This is what she should have said:
"Clint, there you are! Were you down in that cellar the whole time? Well thanks for cleaning that up, but it is time for bed! We have a long trip in the morning. We are going to see your grandma and grandpa. The eclipse is going to be so exciting..."