The filming method for BloodSpell, where the crew created invisible badgers to use as cameras in the computer-generated set, was referenced in the Charles Stross novel "Halting State".
BloodSpell was originally filmed as a series. It was then re-edited and re-released as the feature film represented here. A series of 'making of' commentaries are also widely available.
BloodSpell was intended to be released on DVD. It has indeed been released on DVD but not in the physical medium. To that end, there is a detailed and thought provoking entry on BloodSpell's own website regarding this topic and the potential ramifications of shooting using a game engine.
BloodSpell was shot using the Neverwinter Nights game engine.