Extraterrestrial

April

Melanie

Seth

Deputy Mitchell

Nancy

Clerk

Farmer

Mike

Military officer

Sheriff Murphy

Travis

Matty

In the scene where one character is probed with a spiked probe, the filmmakers consulted probe professionals.

In the scene where April (Brittany Allen) is speaking with her father during a Skype call, on her desktop you can see a pirated copy of Grave Encounters (2011), directors The Vincent Brothers first movie they directed. Extraterrestrial being the second.

The man in black at the end of the movie resembles "The Smoking Man" from X-Files a lot