Principal photography took place entirely on one day - writer/director Peter Murfet's 32nd birthday.
The line in "alien" language which is translated in the subtitles as "Redeem Your Honour", is actually "Rheilfordd Ffestiniog", & is the Welsh language name for the famous Ffestiniog Narrow Gauge Railway in Wales.
The "alien" language line which is translated in subtitles as "Kill them all" is a mispronounced Welsh phrase, which actually translates as "Five Yellow Cats".