Saw this the weekend it came out and was completely amazed by it! I found the plot amazing, original, and completly unexpected. Despite seeing it so long ago the movie is still giving me a "feels good vibe".
You can see this in the trailer but apparently those locals they were filming asking them about the aliens. They are actually referring to the real inhabitants of that slum which was apparently cleared out by the government recently, the inhabitants were moved to a different camp.
Also, Copley for his role improvised a majority of his dialogue which for a "first time" actor is amazing!