Isaac's laptop has several stickers with Cult of the Dead Cow's logo. Cult of the Dead Cow is a legendary hacker group.
Isaac wears a Prodigy t-shirt the first time we see him. A nod to the movie's composer Liam Howlett, founder of The Prodigy.
A digital clock reads 11:38 at one point in the movie. 1138 is a common easter egg used in movies and TV which is a reference to George Lucas's directorial debut film THX 1138 (1971).
The way the game Curs>r loads, and the sound it makes, is reminiscent of the Spectrum, a computer released in 1982 that was cassette based like the cursed game in the movie.
Much of the film was shot in London - including Wembley and Holloway prison.