The actors portraying the roles of Alex and Murphy spoke exclusively in their character dialects (Cockney and Scottish, respectively) during the entire duration of the film's production.
Sebastian Hull (who played The Medic) would quite often go off by himself and scream in between takes to create his eerie vocal quality.
The part of Teddi was played by the director's sister, Ginny. Previous to the film they performed together in numerous theatre productions.
Lauren Wertz (who played the title character Penny) did all of her own stunts.
Director Dan Glaser participated in a two month medical study to help fund the production.