The series has been called "an undisputed landmark in children's television" and a "groundbreaking fantasy series" because it "combined scientific fact and fiction with pagan mythology and rural folklore".
The series is often cited by those who grew up in the Seventies as the most frightening thing seen on television. Simon Pegg cited this as a particular favourite from his childhood for Frost and Pegg's Perfect Night In (2007), Charlie Brooker has reviewed it and Stewart Lee narrated a documentary, "Happy Days", about it for BBC Radio 4 in October 2012.
Gareth Thomas expressed surprise in his 2002 interview (included on the DVD release of that year) about the series, that it had never been repeated on UK television.
Rebroadcast in the United States as part of "The Third Eye" mini-series, first aired in 1983 on the children's television network Nickelodeon.
The 2002 DVD release of the series included specially shot interviews with Gareth Thomas and Peter Graham Scott. Unfortunately, the 2011 DVD release of the series did not include these extras.