Of course the movie is an entire fantasy, but what's the problem of that?
When a fantasy shows us something interesting and give us some good time, it doesn't matter.
The city where the girl goes doesn't exist, but the name seems a clear reference to a real place, Mamirauá.
However, different than in the movie, Mamirauá is a safe study reserve. They receive tourists as well, in a very controlled way, I recommend.
The movie illustrate the dangers in criminal activities in Amazon, but as a family movie, it had to be a fantasy and end in a beautiful way, while the reality is much more harsh.
I don't think the movie was actually shot in Amazon. The water doesn't match, the travel itinerary doesn't match. However, just for making me remember the time I spent there, it deserves an 8.
I noticed some bad reviews around and I can only think they are created by people who lost the capability to enjoy some fantasy in their lifes.