David Wenham's last scene in the film was difficult for him because he is a bit claustrophobic, but according to the director he powered through it like a trouper.
The original concept was to be ghost hunters trapped in a haunted house.
Composer Michael Lira had some fun with the choir's lyrics of Nekrotronic;
You can listen out for Internet terminology recited backwards throughout the film including;
Mar Ga Tad - data-gram
Dah Re Nab - banner ad
Noh Ki To Me- emoticon
During the finale as a Demon rises from the plasma pool, a choir is heard chanting Latin; "Stagnum Calidum" and very quietly "Flexilis Anatis"; which translate as "Hot Bath" (hot tub) and "Rubber Duck."
It premiered at TIFF in Canada in September 2018 as part of the Midnight Madness line-up.
The demon's company logo spells out 666, which is the number of the beast explained in the Bible. In real life, many companies logos have this embedded, most notably C.E.R.N and Google Chrome.