In the episode, the alien time traveller the Doctor (Matt Smith) and his human companions Amy Pond (Karen Gillan) and Rory Williams (Arthur Darvill) find themselves trapped in what appears to be a 1980s hotel with constantly changing corridors.
The Doctor surmises the hotel and its rooms were, by design, meant to make the victims fall back on their faith by scaring them to allow the creature to possess them.
Gibbis, a survivor of the creature, asks for a lift home and the Doctor then takes Amy and Rory to London, believing it best for the two to stop travelling with him before they end up getting killed.
The episode also introduces the Tivolians, a race of cowardly aliens who survive by docilely allowing themselves to be conquered by other species on a regular basis.
Showrunner Steven Moffat originally pitched the idea of a hotel with shifting rooms to writer Toby Whithouse for the previous series.
[7] Whithouse was more pleased with "The God Complex" than "School Reunion" and "The Vampires of Venice", his previous Doctor Who scripts, as the tone was darker which he was "more comfortable" writing.
[9] The first line of dialogue Whithouse wrote was the Doctor's translation of the Minotaur's words: "An ancient creature, drenched in the blood of the innocent, drifting in space through an endless shifting maze.
[10] Amy and Rory's departure in the episode was only temporary; they return for the series finale, "The Wedding of River Song"[11] and appear briefly at the end of the 2011 Christmas Special.
[10] The hotel and setting has been compared to Stanley Kubrick's film The Shining, using similar composition such as long corridor shots and odd angles.
[18] Joe also quotes the old English nursery rhyme "Oranges and Lemons", singing "Here comes a candle to light you to bed, here comes a chopper to chop off your head!".
[21] Overnight ratings showed that 5.2 million viewers watched the episode on BBC One, beaten by direct competitor All-Star Family Fortunes on ITV1.
Radio Times reviewer Patrick Mulkern called Whithouse's script "clever and original" and Walliams "endearing" as Gibbis, believing it was another entry into the series' "fabulous" stand-alone episodes.
[17] Neela Debnath, writing for The Independent, also gave a positive review, praising the creepiness, Amara Karan and Dimitri Leonidas' performances, and the sadness in the ending.
[19] Dan Martin of The Guardian praised the exits of Amy and Rory and highlighted Karen Gillan and Smith's performance, noting how more of his dark side is shown.
[26] Digital Spy's Morgan Jeffery wrote that Nick Hurran "excelled" in directing and that the episode worked "incredibly well" on an emotional level.
[28] Dave Golder of SFX also gave "The God Complex" three and a half out of five stars, questioning some logical aspects but noting that it was "extremely witty, particularly when it comes to David Walliams's cowardly moleman Gibbis".
Risely noted that "things certainly chugged along with a witty, sparkling vibrancy at least early on", but the tone "lost its way halfway through" culminating in a "hollow and rushed" final scene where he left Amy and Rory.