In the scene where Tim, Daisy and Brian have just finished watching the Star Wars trilogy, a funny alien-language song can be heard. This is the Ewok song which plays in the final scene of the original version of Star Wars: Episode VI - Return of the Jedi (1983) (the 1997 Special Edition changed the music) being sung by Simon Pegg, Nick Frost and Edgar Wright. They couldn't get permission to use the John Williams score for the Star Wars end credits although they were allowed to record their own version, but they didn't think they could convincingly recreate it so their composer came up with a tune and they sang the Ewok song over it, the lyrics to which were provided by Pegg who knew them by heart from being a big Star Wars fan as a child.
Tim mentions a series of undisputed facts, one of which is "every odd-numbered Star Trek movie is shit". Ironically, Simon Pegg went on to play Scotty in Star Trek (2009), which is the eleventh installment in the franchise (and regarded as one of the best).
When Daisy is out looking for Colin, the dog she mistakenly thinks is him is Else, the mother of Ada (who plays Colin).
Movie reference: the final scene is a reference to An American Werewolf In London - followed by Prokofiev's Peter and the Wolf music.
Movie reference: the flashback to Tim's stepdad chasing him through a hedge maze is a reference to Jack and Danny Torrance from Stanley Kubrick's The Shining.