This place is not a hotel. It's just the house of an older couple. And as nice as they are, this is somewhere in between false advertising and a plain old scam.
We booked the double room, which doesn't say "shared bathroom" in the title or the confirmation, but does say "detached private bathroom" if you click on "room information". In reality, it's not private by any stretch of the imagination -- first there's nothing preventing any other guests or the hosts themselves using the same bathroom. Second, you go to the restroom down the stairs, through the living room, in which the hosts sit in, so not much of privacy. Oh, and you're asked to take your shoes off before entering the house, so you get to walk in the public areas of the "hotel", including the bathroom, in your socks or barefoot.
24-hour fitness center and spa tub, I have no clue what these could be. 3.5 stars is probably something the hosts awarded themselves. All these “details” contribute to the pretense that this place is a hotel. By far the most ridiculous "hotel" experience I've had in my life. Stay away!