The host responds very fast and was flexible with the check-in when our flight was delayed and even helped with our bags. We particularly enjoyed the view from the balcony with the nice couch and the whole apartment was cozy, clean and well equipped with everything we needed for our stay (we were gone most of the time for work so we did not use the kitchen but it looks like it would be fun to cook there as well).
Really the only thing that was not perfect was that the toilet is rater close to the wall so if you have long legs your knees might touch the wall. It's really not too bad, but it is a bit weird, personally I found it really funny.
So all in all I would totally recommend staying here if you want a place in Belém, we certainly had a good time.