Aside from certain technologies seen, such as 1980's headphones, there is very little from the actual 1980's in this movie. Most of the fashions, makeup and hairstyles seem very much from the 21st Century, especially during the nightclub scene.
Towards the start of the movie, one character shows the others a flier he has made. However, this flier is too high-resolution and sharp for the 1980s, where fliers were usually photocopied/xeroxed or typeset. It is clear the flier was designed on a computer and printed with a modern printer.
Angela, Jackson, Elliot, and Beth all greet each other in various parts of the film with 'Hey', which was not common practice until the 1990's. At that time in Britain the informal (common) way of greeting friends was 'Alright' or 'Hi'.