The film was shot within one week in the Isle of Wight, including the shots of Portsmouth and Southampton which were shot on return to mainland on a ferry.
The cake used was specially made for the film.
The portal device was built out of cardboard, plastic, resin, wiring and a UV light that had a laser placed on top. It was originally supposed to loosely resemble that of the portal gun in the video game, but designs were changed later on during development.
Although the final scene is set in Southampton, England it was actually filmed on location in Portsmouth, England.